BSWA308 309 User Manual 3v3

User Manual:

Open the PDF directly: View PDF .
Page Count: 118

Download
Open PDF In Browser	View PDF

BSWA TECH

BSWA 308/309
Sound Level Meter

User Manual

GB/T 3785.1
GB/T 3785.2
JJG 188-2002
IEC 60651
IEC 60804
IEC 61672-1

BSWA 308/309 Sound Level Meter User Manual
BSWA-III-C021-04-P0274
v3.3
Copyright © 2016 BSWA Technology Co., Ltd
The specification of product is subject to changes without notice
www.bswa.com.cn
Apr. 2016

BSWA 308/309

BSWA Technology Co., Ltd

Change History
Version

Date

Changes

1.00

2010.9.17

Original version.

1.04

2011.3.11

Add new features.

Handle by
Zhao Dawei,
Qiao Jie
Zhao Dawei,
Qiao Jie,
Huang Shan

2.00

2011.9.19

2.05

2013.8.14

3.0
3.1

2015.3.25
2015.6.30

3.2

2015.10.29

3.3

2016.04.26

Huang Shan,

Add RS-232 protocol.

Qiao Jie

Update the storage module, add current save and
GPS module.

Huang Shan,
Wang Linzhang,
Zhao Qingyun

Update new version 308/309 features. Add

Qiao Jie,

firmware update introduction.

Huang Shan

Add corrections and other data required by IEC

Qiao Jie,

standard.

Huang Shan

Add application note in RS-232 hardware

Qiao Jie,

connecting.

Huang Shan

Modify 1/1 octave and add 1/3 octave.

Qiao Jie,
Huang Shan

THIS MATERIAL, INCLUDING DOCUMENTATION AND ANY RELATED COMPUTER
PROGRAMS, IS PROTECTED BY COPYRIGHT CONTROLLED BY BSWA. ALL RIGHTS
ARE RESERVED. COPYING, INCLUDING REPRODUCING, STORING, ADAPTING OR
TRANSLATING, ANY OR ALL OF THIS MATERIAL REQUIRES THE PRIOR WRITTEN
CONSENT

OF

BSWA.

THIS

MATERIAL

ALSO

CONTAINS

CONFIDENTIAL

INFORMATION, WHICH MAY NOT BE DISCLOSED TO OTHERS WITHOUT THE PRIOR
WRITTEN CONSENT OF BSWA.

1

BSWA 308/309

BSWA Technology Co., Ltd

Contents
Change History ............................................................................................................... 1
Contents ......................................................................................................................... 2
Appearance .................................................................................................................... 6
Buttons of Operation ....................................................................................................... 7
1. Introduction ................................................................................................................. 8
1.1 General Description................................................................................................. 8
1.2 Applications ............................................................................................................. 8
1.3 Features.................................................................................................................. 8
1.4 Function Upgrades .................................................................................................. 9
1.5 Spectification........................................................................................................... 9
1.6 Information for Periodic Tests ................................................................................ 12
1.7 Key Component .................................................................................................... 13
1.8 Packing List........................................................................................................... 13
1.9 Packing Drawing ................................................................................................... 14
1.10 China Certification of Pattern Approval (CPA) ...................................................... 15
1.11 China Metrology Certification (CMC) .................................................................... 16
1.12 CE Certification ................................................................................................... 17
2. The Appearance and Operation................................................................................. 18
2.1 Keypad.................................................................................................................. 18
2.2 Microphone Connector .......................................................................................... 19
2.3 Windscreen ........................................................................................................... 20
2.4 Data and Power Supply Connector ........................................................................ 21
2.5 Battery .................................................................................................................. 22
2.6 GPS ...................................................................................................................... 23
3. Measurement Screen ................................................................................................ 25
3.1 Icons and Meaning of Screen Display .................................................................... 25
3.2 Screen of Level Meter Mode .................................................................................. 27
3.3 Screen of 1/1 Octave Mode ................................................................................... 29
3.4 Screen of 1/3 Octave Mode ................................................................................... 29
2

BSWA 308/309

BSWA Technology Co., Ltd

4. Operation and Setting of the Menu ............................................................................ 31
4.1 Function ................................................................................................................ 31
4.2 Calibration ............................................................................................................. 32
4.2.1 Calibration by Measurement ............................................................................. 32
4.2.2 Calibration by Cal.Factor .................................................................................. 32
4.2.3 Conversion of Cal.Factor and Sensitivity ........................................................... 32
4.2.4 Process of Calibration by Measurement ............................................................ 33
4.3 Measurement ........................................................................................................ 35
4.3.1 MEAS.Setup ..................................................................................................... 35
4.3.2 MEAS.Range.................................................................................................... 37
4.3.3 ICCP Power ...................................................................................................... 38
4.3.4 Profile 1~3 ........................................................................................................ 38
4.3.5 Alarm Threshold ............................................................................................... 39
4.3.6 Extended Function ............................................................................................ 39
4.3.7 Statistical .......................................................................................................... 39
4.3.8 Time History ..................................................................................................... 40
4.3.9 Octave .............................................................................................................. 40
4.3.10 Custom Measure ............................................................................................ 40
4.3.11 Timer .............................................................................................................. 41
4.3.12 24h Measurement by Timer ............................................................................ 42
4.4 Setup .................................................................................................................... 43
4.4.1 Contrast............................................................................................................ 43
4.4.2 Backlight........................................................................................................... 43
4.4.3 Battery .............................................................................................................. 43
4.4.4 Trigger .............................................................................................................. 44
4.4.5 Date & Time...................................................................................................... 44
4.4.6 Auto PWR Off ................................................................................................... 46
4.4.7 RS-232 ............................................................................................................. 46
4.4.8 File Manager .................................................................................................... 47
4.4.9 Boot Mode ........................................................................................................ 48
3

BSWA 308/309

BSWA Technology Co., Ltd

4.4.10 USB Mode ...................................................................................................... 49
4.4.11 GPS................................................................................................................ 50
4.4.12 Setup Template ............................................................................................... 50
4.4.13 About .............................................................................................................. 51
4.5 Language .............................................................................................................. 51
4.6 Output ................................................................................................................... 51
4.6.1 AC OUT ............................................................................................................ 51
4.6.2 DC OUT ........................................................................................................... 52
4.6.3 Printer .............................................................................................................. 52
4.7 Factory Settings .................................................................................................... 53
5. RS-232 Communication Protocol .............................................................................. 54
5.1 Hardware Configuration and Settings of Interface .................................................. 54
5.2 Transfer Protocol ................................................................................................... 54
5.2.1 Start/Stop of the Block Transfer ........................................................................ 55
5.2.2 Device ID.......................................................................................................... 55
5.2.3 ATTR Attribute Character .................................................................................. 55
5.2.4 BCC (Block Check Character)........................................................................... 56
5.2.5 Block Transfer Format....................................................................................... 56
5.2.6 Recovery from Transmission Errors .................................................................. 57
5.2.7 Flow Control ..................................................................................................... 58
5.2.8 Multi-Machine Operation ................................................................................... 58
5.2.9 Rated Parameters ............................................................................................ 59
5.3 Instruction ............................................................................................................. 59
5.3.1 Instruction List .................................................................................................. 61
5.3.2 Instruction Format ............................................................................................. 64
5.3.3 Instruction Describe .......................................................................................... 65
6. Operation Notes........................................................................................................ 99
6.1 Operation .............................................................................................................. 99
6.2 Common Issue And Solutions ................................................................................ 99
6.3 Calibration ........................................................................................................... 100
4

BSWA 308/309

BSWA Technology Co., Ltd

6.4 Firmware Update................................................................................................. 100
6.4.1 Install USB Driver ........................................................................................... 100
6.4.2 Firmware Update Procedure ........................................................................... 101
6.5 Warranty ............................................................................................................. 102
6.6 Customer Service Phone Number ....................................................................... 103
Annex 1 Glossary ....................................................................................................... 104
Annex 2 Adjustments at the Calibration Check Frequency ........................................... 106
Annex 3 Corrections for the Typical Effects of Reflections from the Case of Sound Level
Meter and Diffraction of Sound around the Microphone ................................. 107
Annex 4 Corrections of Windscreen in Free Field ........................................................ 108
Annex 5 Corrections of Electrostatic Actuator .............................................................. 109
Annex 6 Typical Frequency Response and Corresponding Upper Limit ....................... 110
Annex 7 Specification of 1/1 Octave Band Filter ...........................................................111
Annex 8 Specification of 1/3 Octave Band Filter .......................................................... 112
Annex 9 Mid-band Frequencies for 1/1 Octave Band and 1/3 Octave Band Filters ....... 115

5

BSWA 308/309

BSWA Technology Co., Ltd

Appearance

Microphone and preamplifier

LED indicator
1/4” thread

LCD with
backlight
Battery
LR6/AA/AM3

Non-slip
surface

Cover lock:
Left◄: unlock
Right►: locked
Power Jack

(7V~14V)

Trigger

6

DC Output

AC Output

BSWA 308/309

BSWA Technology Co., Ltd

Buttons of Operation

LED indicator



LCD Screen





Arrow keys
<▲><▼>
<◄><►>






7

BSWA 308/309

BSWA Technology Co., Ltd

1. Introduction
1.1 General Description
The new BSWA 308/309 are new generation octave sound level meter upgrade from base
BSWA 308/309 to meet the market demand. It fulfill the 1/1 octave requirement of IEC
standard and China GB/T standard.
The BSWA 308/309 is a digital sound level meter which design and manufacture by BSWA.
The use of high precision 24 Bits AD converter makes the instruments to be an ideal choice
for performing many kinds of measurement, for example, environmental noise, vehicle noise
and industrial application.
The new types upgrade the dual-core (DSP+ARM) architecture to single chip ARM with float
point unit, and update all fix-point calculation to float-point which significantly improves the
accuracy and stability. Re-design analog front end circuit also lower the noise floor and linear
range of product. The new developed algorithm brings a single measurement range which
can cover more than 120dB dynamic range while still meets the standard.
BSWA 308 is Class 1 and BSWA 309 is Class 2. Both instruments have certificated by the
China CPA (Certification of Pattern Approval) and CMC (China Metrology Certification).

1.2 Applications
 Basic noise measurement
 Environmental noise assessment
 Product quality check
 Evaluation of noise reduction engineering

1.3 Features
 Class 1 (BSWA 308) and Class 2 (BSWA 309)
sound level meter
 Comply with IEC 61672-1:2013, ANSI S1.4-1983 and ANSI S1.43-1997
 Real-time 1/1 and 1/3 Octave in accordance with IEC 61260-1:2014 and ANSI S1.11-2004
 Linearity range: 22dBA~136dBA (BSWA 308), 25dBA~136dBA (BSWA 309)
 Single range to cover 123dB (BSWA 308) / 122dB (BSWA 309) dynamic range
 Frequency weighting: A/B/C/Z. Time weighting: Fast/Slow/Impulse
 3-Profile and 14 custom define measurement are calculate in parallel with different
8

BSWA 308/309

BSWA Technology Co., Ltd

frequency/time weighting
 Calculate SPL, LEQ, Max, Min, Peak, SD, SEL, E
 LN statistical and time history curve display
 User define integral period measurement, integral period up to 24h
 High speed ARM core with FPU (Float Point Unit) to achieve wide frequency response,
large dynamic range and low noise floor
 4G MicroSD card (TF card) mass storage
 RS-232 remote control port
 Mini thermal printer for measurement data print
 Internal GPS module (option), support GPS timing

1.4 Function Upgrades
 Single chip high speed ARM with FPU

 USB port function implemented

 White backlight LCD

 Update firmware via USB (also power supply)

 Integral period from 1s~24h

 Timer feature support auto measurement

 0.1s, 0.2s, 0.5s logger step added

 Internal GPS (option) with GPS timing

 5 templates to save user setting

 Single range to cover 123dB dynamic range

 B-weighting added to for ANSI standard

 Reduce the noise floor (only for Class 1)

 Automatic power on with external

 Upper limit of measurement:

supply, ease of integration

136dBrms/139dBpeak (40mV/Pa)

1.5 Spectification
Specifications
Type
Accuracy

BSWA 308

BSWA 309

Class 1 (Group X)

Class 2 (Group X)

GB/T 3785.1-2010, IEC 60651:1979, IEC 60804:2000
Standard
IEC 61672-1:2013, ANSI S1.4-1983, ANSI S1.43-1997

Octave1

Real-time 1/1 Octave: 8Hz~16kHz

Real-time 1/1 Octave: 20Hz~8kHz

Real-time 1/3 Octave (Option): 6.3Hz~20kHz

Real-time 1/3 Octave (Option): 20Hz~12.5kHz

GB/T 3241-2010, IEC 61260-1:2014

GB/T 3241-2010, IEC 61260-1:2014

ANSI S1.11-2004. Base 10 system.

ANSI S1.11-2004. Base 10 system.

9

BSWA 308/309

BSWA Technology Co., Ltd

Supplied
Microphone

MPA231T: 1/2” prepolarized

MPA309T: 1/2” prepolarized

measurement microphone, Class

measurement microphone, Class

1. Sensitivity: 40mV/Pa. Frequency 2. Sensitivity: 40mV/Pa. Frequency
Range: 3Hz~20kHz.

Mic Interface

Range: 20Hz~12.5kHz.

TNC connecter with ICCP power supply (4mA)

Detector / Filter

Fully float-point digital signal processing (digital detector and filter）
Infinite or 1s~24h user define integral period.

Integral Period
Repeat time: Infinite or 1~9999
Logger Step

0.1s, 0.2s, 0.5s, 1s~24h
LXY(SPL), LXeq, LXYSD, LXSEL, LXE, LXYmax, LXYmin, LXPeak, LXN. Where X is the
frequency weighting: A, B, C, Z; Y is time weighting: F, S, I; N is the

Measurement
statistical percentage: 1~99. 3-Profile and 14 custom define
Functions
measurement are calculate in parallel with different frequency/time
weighting
Automatic measurement based on user define date/time and save the
24h Measurement
history data
Frequency
Parallel A, B, C, Z (It can also be applied to 1/1 and 1/3 Octave)
Weighting
Time Weighting

Parallel F, S, I and Peak detection
Sound: 19dB(A), 25dB(C), 31dB(Z)

Self-Noise2

Sound: 20dB(A), 26dB(C), 31dB(Z)

Electrical: 13dB(A), 17dB(C), 24dB(Z) Electrical: 14dB(A), 19dB(C), 24dB(Z)

136dB(A)
Upper Limit

2

136dB(A)

Increase to 154dB(A) with 5mV/Pa Increase to 154dB(A) with 5mV/Pa
Microphone

Microphone

10Hz~20kHz

20Hz~12.5kHz

22dB(A)~136dB(A)

25dB(A)~136dB(A)

Octave: 30dB~136dB

Octave: 33dB~136dB

123dB (13dB(A)~136dB(A))

122dB (14dB(A)~136dB(A))

Frequency
Response1
Level Linearity
2, 3, 4

Range

Dynamic Range

10

2

BSWA 308/309
Peak C Range2, 3

BSWA Technology Co., Ltd
47dB~139dB

50dB~139dB

Maximum input voltage: 5Vrms (7.07Vpeak). Input impedance of
Electrical Input
preamplifier: >6GΩ
Range Setting

Single range to cover whole dynamic range

Resolution

24Bits

Sampling Rate

48kHz

Time History

Time domain noise curve display. Duration time: 1min, 2min, 10min
160x160 LCD with white backlight, 14 step contrast level, 1s display

LCD Display
update rate
Mass Storage

4G MicroSD card (TF card)
Post-processing software VA-SLM can read, analyze and generate

Post-Processing
reports of store data.
Export Data

Directly connect to the computer to read the memory card (USB disk)
AC Output (max 5VRMS, ±15mA), DC Output (10mV/dB, max 15mA),

Output
RS-232 serial interface and USB (USB disk mode or modem mode)
Alarm

User define alarm threshold. LED indicate the alarm status
5 templates to save user setup for different application, template can be

Setup Template
save in MicroSD card
Automatic power on and start measurement when power supply
Auto Power On
available, ease of integration
4x1.5V alkaline batteries (LR6/AA/AM3), sustainable use of approx.10
Power Supply

hours (depends on battery). It also can be supply by external DC power
(7V~14V 500mA) and USB power (5V 1A)
Built-in backup battery has been calibrated at factory to the error <26s in
30days (<10ppm, (25±16) ºC). It can keep RTC running when replacing

RTC
the main batteries.
GPS timing function available (option with GPS module)
Language
Firmware Update

English, Chinese, Portuguese, Spanish, German, French
Update firmware via USB port
11

BSWA 308/309

BSWA Technology Co., Ltd

Conditions

Temperature: -10ºC~50ºC. Humidity: 20%~90%RH

RT Temperature

Real-time temperature display on the main screen

Size (mm)

W70 x H300 x D36

Weight

Approx. 620g, including 4 alkaline batteries
Option
Receiver Type: 50 Channels; Time-To-First-Fix: Cold Start 27s, Warm
Start 27s, Hot Start 1s; Sensitivity: Tracking -161dBm, Reacquisition
-160dBm, Cold Start -147dBm, Hot Start -156dBm; Horizontal position

GPS
accuracy: 2.5m, Timing accuracy: 30ns, Velocity accuracy: 0.1m/s;
Update Rate: 1Hz, Operation Limits: Dynamic≤4g, Altitude<50000m,
Velocity<500m/s
Calibrator
Printer

CA111, Class 1, 94dB/114dB, 1kHz
Mini thermal or dot-matrix printer, RS-232 port

Note 1: Ignore the result outside 20Hz~12.5kHz for type BSWA 309 alone due to microphone
frequency response of Class 2.
Note 2: The data was measured with 40mV/Pa microphone for BSWA 308 and BSWA 309.
Note 3: Measurement according to GB/T 3785 and IEC 61672.
Note 4: Measurement according to GB/T 3241 and IEC 61260.

1.6 Information for Periodic Tests
 Reference sound level: 94.0dB.
 Reference incidence direction: parallel to the incident direction of the microphone.
 Reference point of microphone: the central point of microphone diaphragm.
 Reference incidence direction: direction perpendicular to the microphone diaphragm.
 Reference attenuation of octave spectra: 0dB.
 Reference input signal level of octave spectra: 40mV (94dB for sensitivity of 40mV/Pa).

12

BSWA 308/309

BSWA Technology Co., Ltd

1.7 Key Component
Component Name

Manufacturer

Type

Description

BSWA Technology

MP231

Class 1 microphone

Co., Ltd.

MP309

Class 2 microphone

Microphone

1.8 Packing List
No.

Type

Description
Standard

1

BSWA 308/309

Sound level meter without microphone

2

CC308 Case

Carrying case

3

MA231T

ICCP preamplifier with TNC connector

4

MP231/MP309

Class 1 (308) or class 2 (309) microphone

5

WS002-9 Windscreen

90mm diameter windscreen for 1/2” microphone

6

MicroSD Card

4G memory card to store data

7

Battery

Alkaline battery (LR6 / AA / AM3) x 4

8

Power Adapter

Power adapter with 9V/500mA

9

MiniUSB Cable

Use to connect computer

10

Quick Start Guide

Quick start guide

11

Certificate of Calibration

Certificate of factory calibration

12

CD

13

Certificate of Conformity

Certificate of conformity

14

GPS

GPS module and antenna

15

Sound Calibrator

Include post-process software, user manual (pdf), driver,
firmware and other utility
Option

CA111: class 1 calibrator, 94dB/114dB
CA114: class 2 calibrator, 94dB
CA115: class 2 calibrator, 114dB
16

Thermal Printer

Mini thermal printer without ribbons, RS232 connector

17

Tripod

Stand for sound level meter

18

Printed User Manual

Printed user manual

19

Test Report

Test report from metrology institute

13

BSWA 308/309

BSWA Technology Co., Ltd

1.9 Packing Drawing

☆Note: The detail of packing items may vary to follow orders.

14

BSWA 308/309

BSWA Technology Co., Ltd

1.10 China Certification of Pattern Approval (CPA)

CPA of BSWA 308

2014S226-11

CPA of BSWA 309

2012S233-11

15

BSWA 308/309

BSWA Technology Co., Ltd

1.11 China Metrology Certification (CMC)

CMC of BSWA 308

京制 01020122 号

CMC of BSWA 309

京制 01020122 号

16

BSWA 308/309

BSWA Technology Co., Ltd

1.12 CE Certification

17

BSWA 308/309

BSWA Technology Co., Ltd

2. The Appearance and Operation
BSWA 308/309 uses the same body and the keypad layout. LCD screen, keypad and LED
indicators lay on the front of instrument.

2.1 Keypad
Sound level meter has 10 keys, namely:





<▲>



<◄>

<▼>

<►>







:
Long press 2 seconds of this key will power on the sound level meter. When sound level
meter keep in stop state, long press 2 seconds will trigger the shut-down-dialog-box, and
then press  to power off sound level meter.
☆Note:  is invalid when the sound level meter is running measurement.
:
Exit the menu or return to previous menu. Press  also can clear the history curve
at the time history screen.
:
Enter the menu of next level, or confirm the changes of the parameters, or save current
data as CSD format in stop state.
:
Press to open or close the LCD backlights. Backlight delay can be set in the menu. Refer
to 4.4.2 Backlight to earn more details.
18

BSWA 308/309

BSWA Technology Co., Ltd

:
Start or stop the measurement.
<▲>:
Up arrow used to select the menu item or adjust the parameters.
<▼>:
Down arrow used to select the menu item or adjust the parameters.
<◄>:
Left arrow used to select the menu item, or adjust the parameters, or switch measure
screens.
<►>:
Right arrow used to select the menu item, or adjust the parameters, or switch measure
screens.
:
Press to enter the main menu list.

2.2 Microphone Connector
The TNC connector on the top of the sound level meter is used to connect to microphone and
preamplifier (microphone and preamplifier are usually mounted together). The TNC is
threaded coaxial connector.

BSWA 308 is equipped with Class 1 microphone, while BSWA 309 is equipped with Class 2:
MPA231T:
1/2” pre-polarized measurement microphone, class 1. Sensitivity: 40mV/Pa. Frequency
range: 3Hz~20kHz. Mounted with ICCP preamplifier and powered by 4mA/24V.
MPA309T:
1/2” pre-polarized measurement microphone, class 2. Sensitivity: 40mV/Pa. Frequency
range: 20Hz~12.5kHz. Mounted with ICCP preamplifier and powered by 4mA/24V.
19

BSWA 308/309

BSWA Technology Co., Ltd

Microphone and preamplifier are mounted together by thread. Unless special situation,
please do not separate each other. The microphone is a precision measurement sensor,
long-term exposure to high humidity or dust environment would impact microphone.
Microphone that is not in use should be placed in a attached box.
The microphone is ICCP power supply. The supply current specifications are 4mA, voltage
24V. It will damage the microphone if voltage over 30V. BSWA 308/309 sound level meter
has internal ICCP power which can connect to microphone directly.

Insert microphone to TNC connector. Then rotate the thread until the connection is tight.

2.3 Windscreen
Sound level meter equipped with WS002-9 windscreen for use in windy outdoor
environments. No need to use windscreen when used in a windless environment (such as
indoor measurement).

Insert the windscreen onto the microphone until stop according to above diagram. Refer to
Annex 4 Corrections of Windscreen in Free Filed to earn more detail.

20

BSWA 308/309

BSWA Technology Co., Ltd

2.4 Data and Power Supply Connector
There are 7 interfaces at the bottom of the sound level meter. Open the rubber cover to see
these interfaces.

PWR:
Power connector, using the standard DC socket (2.1mm core diameter), can connect to
the 7~14V 500mA external power supply.
☆Note: Exceed 14V could damage the sound level meter!
MiniUSB:
MiniUSB port which connects to a computer can be select as USB Disk Mode or
Modem Mode, refer to 4.4.10 USB Mode to earn more detail. Additional, MiniUSB can
be used as another external power, but the power supply must meet the requirement of
5V/1A.
USB Disk Mode：The files inside the MicroSD card can be access directly at this mode,
no need to install driver.
Computer can recognize the MiniUSB as serial port (virtual serial port, need to install
driver) and communicate with sound level meter by RS-232 protocol, refer to 5. RS-232
Communication Protocol to earn more detail.
☆Note：At least 1A power current capacity must be meet for power supply and cable
(cable with ferrite core is not recommend for power supply). Please select the working
mode in time after connected to the computer. Otherwise, the computer can’t recognize
the USB. The MiniUSB and RS-232 port cannot working at the same time when select
Modem Mode.
MicroSD:
MicroSD socket, standard MicroSD card can be used to store SWN, OCT and CSD files.
Recommend to use card-reader to format the MicroSD card, rather than format it at the U
21

BSWA 308/309

BSWA Technology Co., Ltd

Disk Mode. Note that the MicroSD card provides with the sound level meter has already
formatted before sale.
☆Note: Keep front side (with silk screen) of MicroSD card down to insert without
hot-plug.
RS-232:
It can be use as standard RS-232 port at Remote mode, and also can be used to
connect thermal printer as Printer mode. Refer to 4.6.3 Printer and 5. RS-232
Communication Protocol to earn more detail.
TRIGGER:
Trigger input interface using a standard 3.5mm headphone jack. Refer to 4.4.4 Trigger to
earn more detail.
DC OUT:
DC output interface using a standard 3.5mm headphone jack. Refer to 4.6.2 DC OUT to
earn more detail.
AC OUT:
AC output interface using a standard 3.5mm headphone jack. Refer to 4.6.1 AC OUT to
earn more detail.

2.5 Battery
Recommend to use 4 cell of alkaline battery (LR6/AA/AM3), paying attention to the battery
polarity (+/-) marked in the battery compartment. Do not mix using of old and new batteries at
the same time. Remove batteries when the device is not in use. The total voltage of 4 cell
battery cannot exceed 14V, otherwise it will damage the sound level meter.
The real test shows that the 4 cell of alkaline battery can support sustainable use of
approx.10 hours (depends on battery) for sound level meter. When use rechargeable battery
Eneloop BK-3HCCA/4BC (Rated capacity 2450mAh), sound level meter can work about 12
hours continuously. When the battery voltage is lower than the minimum voltage requirement
of the sound level meter, it will shut down automatically.
We recommend using external power supply or USB-power-bank rather than batteries for
long time running.
Follow the figure below to install or replace the battery:
22

BSWA 308/309

BSWA Technology Co., Ltd

Turn the button to the left side to unlock the battery compartment cover. Then lift the cover to
open it.

Close and lock the battery compartment after change the battery.

2.6 GPS
GPS antenna cover located on the top surface of sound level meter which select GPS
function as option module.
☆Note: GPS function must be select before delivery to user due to install GPS module
should return the sound level meter to factory.

GPS performance is mainly affected by two factors: the satellite ephemeris and the satellite
signal noise ratio.
23

BSWA 308/309

BSWA Technology Co., Ltd

 Satellite Ephemeris: GPS satellites orbit information. According to ephemeris, satellite
positioning signal and time, the current location can be determined. Ephemeris need to
download from the GPS satellites, but the download speed is very low (approx. 50bps),
and vulnerable to the impact of satellite signal strength. The high bit error rate may lead to
a longer time of download ephemeris, and even download fail. The sound level meter can
keep the ephemeris data in memory for approx. 30 minute after turn off GPS module. The
ephemeris data is only is valid within 2 hours.
 Satellite Signal Noise Ratio: Satellite positioning signal intensity. In rainy days or indoor,
signal strength will be affected.
GPS have 3 boot modes: Cold start, warm start and hot start
 Cold Start: First location, need to download the latest ephemeris and longer time.
 Warm Start: GPS module has the last saved location information, but need to
re-download the ephemeris due to expired. Warm start needs almost same time as cold
start.
 Hot Start: GPS module has valid ephemeris and can reposition in a very short time.

24

BSWA 308/309

BSWA Technology Co., Ltd

3. Measurement Screen
Sound level meter has two measurement modes: Level Meter and 1/1 Octave. User can
select it in the menu of Function.
Level Meter has 8 screens which can be switch through <◄>, <►>. The 8 screens are: Main,
3-Profiles, LN Statistical, Time History, Custom Measurement Page 1, Custom Measurement
Page 2, GPS Page 1 and GPS Page 2.
1/1 Octave has 4 screens: Octave Histogram, Octave Table Page 1~3.

3.1 Icons and Meaning of Screen Display

All icons of Main screen is enable, the meaning of each icons are describe as following:
Start/Stop. Describe the measurement state.
Overload indicator and under-range indicator. Solid arrow
indicates that the current state is overload / under-range. Hollow
arrow indicates that overload / under-range event have occurred
within the integral period。At the beginning of the new integral
period, overload and under-range indicator icon will be clear.
ICCP power state. Displayed when ICCP is turn off.
Trigger state. Displayed when trigger is enable.
RS-232 state. Icon
and icon

will be displayed at the Remote mode,

will be displayed at Printer mode.

25

BSWA 308/309

BSWA Technology Co., Ltd
Timer state. Icon
once. Icon

means the timer is enabled and only run

means the timer is enabled and run in loop.

MicroSD state. Displayed when enable the MicroSD storage.
Power state. The icons form left to right: external power supply,
battery supply (with voltage display) and USB power supply.
Calculation mode of measurement.
Filter state.
Detector state.
Icon of Profile. Indicate the profile number of current display.
Measurement value.
Visualize and dynamic bar graph display of measurement values
within the current range.
Date and time.
Current page number and total page number.
Internal temperature display.
Icon

means the integral period, icon

means the elapsed

time. The measurement stop when elapsed time equal to total
measurement time (Itg.Period * Repeat).
Icons in the same row will display one at the same time. All icons can be display on each
screen and keep the same meaning.

26

BSWA 308/309

BSWA Technology Co., Ltd

3.2 Screen of Level Meter Mode

Main screen. Display the measurement
data, filter, detector, mode and Profile
number. Main screen only display one
group data of 3-Profile. Press <▲>,
<▼> to switch within 3-Profile.

3-Profile. Display the data and
corresponding mode, filter and detector
of 3-Profile measurement at the same
time. 3-Profile data can be saved into
SWN file.

LN Statistical. Display 10 groups of
statistical results. Each group of data
sources (fix mode to SPL, filter and
detector can be customize) and the
percentage value can be set through
the menu.
Time History. Display the current noise
value and time domain curve. The data
sources (one of 3-Profile) and the
time-line length (1min, 2min and 10min)
can be customize.
Press  to clear the screen and
re-display the curve.

27

BSWA 308/309

BSWA Technology Co., Ltd

Custom Measurement Page 1. User
can set the parameters of the 14 sets of
measurement. This screen can display
the first 7 sets.

Custom Measurement Page 2. User
can set the parameters of the 14 sets of
measurement. This screen can display
the last 7 sets.

GPS Page 1. Display GPS information:
GPS state, GPS date, GPS time,
latitude, longitude, altitude and speed.

GPS Page 2. Display number of satellite
which contribute to positioning, and
signal noise ratio of all visible satellites
(0dB~99dB).
☆ Note: Number of visible satellites
may be greater than the number of
positioning satellites

due to some

satellites is unavailable for positioning.

28

BSWA 308/309

BSWA Technology Co., Ltd

3.3 Screen of 1/1 Octave Mode
1/1 Octave Spectra. Display 12 bands
of 8Hz~16kHz and LAeq, LBeq, LCeq, LZeq
as bar graph. Press <▲>, <▼> to
display the detail value of each band. A
threshold can be set for each band. The
LED indicator will turn red when the
data exceed the threshold.

Octave Table Page 1. Display the
measurement data of 8Hz~16kHz. The
LED indicator will turn red and dB value
will display as invert color when the data
exceed the threshold.

Octave Table Page 2. Display the
measurement data of LAeq、LBeq、LCeq、
LZeq. The LED indicator will turn red and
will be display when the data
exceed the threshold.

3.4 Screen of 1/3 Octave Mode
1/3 Octave Spectra. Display 36 bands
of 6.3Hz~20kHz and LAeq, LBeq, LCeq,
LZeq as bar graph. Press <▲>, <▼> to
display the detail value of each band. A
threshold can be set for each band. The
LED indicator will turn red when the
data exceed the threshold.
29

BSWA 308/309

BSWA Technology Co., Ltd

Octave Table Page 1. Display the
measurement data of 6.3Hz~80Hz. The
LED indicator will turn red and dB value
will display as invert color when the data
exceed the threshold.

Octave Table Page 2. Display the
measurement data of 100Hz~1.25kHz.
The LED indicator will turn red and dB
value will display as invert color when
the data exceed the threshold.

Octave Table Page 3. Display the
measurement data of 1.6kHz~20kHz.
The LED indicator will turn red and dB
value will display as invert color when
the data exceed the threshold.

Octave Table Page 4. Display the
measurement data of LAeq、LBeq、LCeq、
LZeq. The LED indicator will turn red and
will be display when the data
exceed the threshold.

30

BSWA 308/309

BSWA Technology Co., Ltd

4. Operation and Setting of the Menu
Press  to access the next level menu. All parameters
related to measurement can be set in the menu.

Menu Tree

4.1 Function
Select Function and press  to enter this menu. 2 kind
of measurement can be select: Level Meter and 1/1 Octave.
Press <▲>, <▼> can select mode of measurement. Press
 to save setting and return to previous menu. Press
 to return to previous menu.

31

BSWA 308/309

BSWA Technology Co., Ltd

4.2 Calibration
Select Calibration and press  to enter this menu.
Many factors include temperature, humidity and air pressure
will impact the microphone's sensitivity. Therefore, user must
run calibration at least once before measurement.
There are two calibration methods: By Measurement and By
Cal.Factor. Method of By Measurement is recommend for
calibration with sound calibrator. Method of By Cal.Factor can manually adjust the calibration
factor by user.
4.2.1 Calibration by Measurement
Select By Measurement and press  to enter this
menu. Refer to Annex 2 Adjustments at the Calibration Check
Frequency to earn more detail of the stated calibrator and
corresponding adjustment value.
Cal.Level can be adjusted between 0dB~199.9dB. Press <◄>,
<►> and <▲>, <▼> can change the Cal.Level and press
 to start calibration. After calibration finished, the new Cal.Factor will be update as the
result and user can press  or  to save or ignore this result. This menu also
displays the calibration history. Ending with symbol M indicate the record was calibrate by the
method of By Measurement.
4.2.2 Calibration by Cal.Factor
Select By Cal.Factor and press  to enter this menu.
Users can adjust the calibration factor manually. Press <◄>,
<►> can select the digit of factor, press <▲>, <▼> can adjust
the value, press  to save and press  to return to
previous menu. Ending with symbol F indicate the record was
calibrate by the method of By Cal.Factor.
4.2.3 Conversion of Cal.Factor and Sensitivity
The sensitivity can be calculated by the following formulas, and the calibration factor also can
be calculated from sensitivity and type into sound level meter directly.
32

BSWA 308/309

BSWA Technology Co., Ltd

Cal.F = 20 * log (Sens / 40) + offset
Sens = 40 * 10 ((Cal.F-offset) / 20)
Where:

Cal.F is the calibration factor, expressed in decibels (dB);
Sens is sensitivity of microphone, expressed in mV/Pa;
offset is the calibration factor, expressed in decibels (dB). This value is the calibration
result by the method of By Measurement with 40mV signal. This offset is inherent deviation
which is different for each sound level meter.
4.2.4 Process of Calibration by Measurement
Calibration by measurement is the recommend method of calibration with sound calibrator.
BSWA can provide class 1 and class 2 sound calibrator comply with the GB/T 15173-2010,
IEC60942: 2003 standard.
The process of calibration by measurement is shown as following:
(1)

Insert the microphone into the cavity of the calibrator until stop without loosening.

(2)

Then open the power of the calibrator and set to a constant sound pressure level (for

example 94dB).

33

BSWA 308/309

BSWA Technology Co., Ltd

(3)

Select Calibration in the menu and then press  to enter By Measurement.

(4)

Adjust Cal.Level in the menu, for example adjust to 93.8dB. There is 5s delay after
press  to run calibration.

(5)

After the end of calibration, sound level meter will update the calibration factor. Press

 to apply the results.

(6)

Return to Main screen and press  to start the measurement. The current

measurement result will be 93.8dB in this example if calibrator is still working.

34

BSWA 308/309

BSWA Technology Co., Ltd

4.3 Measurement
There are 13 items in the menu of
Measurement. Press <▲>, <▼>
can choose and select, press
 to access next level of
menu.

4.3.1 MEAS.Setup
Menu of MEAS.Setup is the most important menu related to
measurement. It can set the parameter of Delay, Itg.Period,
Repeat, SWN Logger, SWN Log.Step, CSD Logger and
CSD Log.Step. Press <▲>, <▼> can choose and select.

Delay:
Delay time between press  and the beginning of the measurement. Press <◄>,
<►> can select the delay time: Sync 1m, Sync 15m, Sync 30m, Sync 1h, 1s~60s.
The delay time can skip the impact come from the key pressing or vibration before the
measurement.
Itg.Period:
Itg.Period is the integral period of each single measurement. At the beginning of each
integral period, all of the integral data and time-hold data will be reset, and the overload
and under-range indicator will be clear. Integral data and time-hold data include LEQ,
Max, Min, Peak, SD, SEL, E and LN. Press <◄>, <►> can select the option: Inf, 1s~59s,
1m~59m, 1h~24h.
Repeat:
Repeat is the number of repeat time of measurement. Total measurement period
=Itg.Period x Repeat. Press <◄>, <►> can select the option: Inf, 1~9999.
SWN Logger:
Press <◄>,<►> to switch. If selected, sound level meter will save the SWN/OCT files.
35

BSWA 308/309

BSWA Technology Co., Ltd

SWN/OCT saves the time history data into file. The data source in Level Meter mode is
Profile 1~3 (select in SWN Save of Profile 1~3 menu) and store as SWN file; in 1/1
Octave mode save all bands of octave and LAeq, LBeq, LCeq, LZeq, store as OCT file.
SWN Log.Step:
SWN Log.Step is the logger step (interval time) to save data as SWN/OCT file. Press
<◄>, <►> can select the option: 0.1s, 0.2s, 0.5s, 1s~59s, 1m~59m, 1h~24h.
☆Note: The SWN Log.Step of 1/3 Octave starts from 0.5s (0.1s and 0.2s are disable).
CSD Logger:
Press <◄>,<►> to switch. If selected, sound level meter will save the CSD files.
CSD save the instantaneous data into file. The data source in Level Meter mode is 14
group results of Custom Measure and store as CSD file; in 1/1 Octave mode save all
bands of octave and LAeq, LBeq, LCeq, LZeq, store as CSD file.
☆Note: If selected, press  at the main screen can save the data into CSD file
manually when measurement is stop.
CSD Log.Step:
CSD Log.Step is the logger step (interval time) to save data as CSD file. Press <◄>,
<►> can select the option: 1s~59s, 1m~59m, 1h~24h.

Profile1
Profile2
Profile3

14 sets of
Custom
Measure

Octave
Data
SWN/OCT
Log.Step:
0.1s~24h

SWN File

OCT File

CSD
Log.Step:
1s~24h
CSD File

☆Note: SWN/OCT file only store integral data. The logger step can be considered as the
integral period. All the data within logger step (integral period) will be store as one line into
SWN/OCT file. CSD file only store instantaneous data without integration. Once the CSD
logger step is reached, 14 group data of custom measure will be store as one line into CSD
file, just as a screenshot.

36

BSWA 308/309

BSWA Technology Co., Ltd

4.3.2 MEAS.Range
Menu of MEAS.Range display the Linearity Range, Dynamic
Range and Peak C Range.
The new developed algorithm brings a single measurement
range that no needs to change the range anymore. The
algorithm can meet the requirement of toneburst response
down to 0.25ms with only 0.1dB error at 4kHz. And the error is
0.4dB for 0.125ms toneburst test at 4kHz.
Linearity Range: The measurement result can be considered to be correct only when the
result located in the linearity range. Otherwise, the error of measurement result is over the
acceptance limits. Sometimes linearity range also can be called measurement range.
Dynamic Range: Dynamic range is the range between the self-generated noise level and
the maximum input signal level. Dynamic range is the maximum range which can be display
on the sound level meter. Note the measurement result near the self-generated noise level
can be considered is non-linear.
Peak C Range: Peak C range is the linearity range of Peak C measurement. The Peak C
measurement result located in this range can be considered to be correct.

37

BSWA 308/309

BSWA Technology Co., Ltd

4.3.3 ICCP Power
Menu of ICCP power control the 4mA/24V constant current
source which can supply all kind of ICCP sensor. Please
disable ICCP power before connect to other kind of sensor or
directly connect to signal source. Press <◄>, <►> can choose
and select.

4.3.4 Profile 1~3
Menu of Profile 1~3 can set the Filter, Detector, Mode and
SWN Save. Press <▲>, <▼> can choose and select.

Filter:
Set the filter of Profile 1~3. Press <◄>, <►> can select the option: A, B, C and Z
(Z-weighting means no weighting and sometimes it is called Flat or Linear).
Detector:
Set the detector of Profile 1~3. Press <◄>, <►> can select the option: Fast, Slow, and
Imp..
Mode:
Set the integral mode of Profile 1~3. Press <◄>, <►> can select the option: SPL, PEAK,
LEQ, MAX and MIN.
SWN Save:
This option is used to set which data should be store in the SWN file, since the data
source of SWN file is Profile 1~3. So this option is no relationship with screen display.
Press <◄>, <►> can select the option: LEQ, PEAK, MAX or MIN.

38

BSWA 308/309

BSWA Technology Co., Ltd

4.3.5 Alarm Threshold
If measurement result of Profile 1~3 exceeds the Alarm
Threshold, the LED indicator above  will turn red.
Alarm threshold can be set to 20dB~200dB. Press <▲>, <▼>
can increase and reduce 1dB. Press <◄>, <►> can add and
reduce 10dB.

4.3.6 Extended Function
Extended Function can set which screen can be display. If the
screen is not selected, it will not be display. Note that Main
screen is designed to be displayed all the time.

4.3.7 Statistical
The data source of statistical is
SPL which is fixed. User can’t
change it. But user can set the
filter and detector of SPL and the
statistical

percentage

value

through this menu.
Mode:
It’s fixed to SPL and cannot be changed.
Filter:
Press <◄>, <►> can set the filter of statistical analysis: A, B, C and Z (Flat).
Detector:
Press <◄>, <►> can set the detector of statistical analysis: Fast, Slow and Imp..
LN1~LN10:
Press <◄>, <►> can set the percentage of 10 group of LN to 1%~99%.
For example: LN1:10=80dB means that in integral period, 10% of measurement data is
39

BSWA 308/309

BSWA Technology Co., Ltd

greater than 80dB. The LN result related to integral period. It will be reset when a new
integral period start.
4.3.8 Time History
Press <▲>, <▼> can set the data source and duration time of
Time History.

Profile:
Press <◄>, <►> can set the data source of time history: Profile1, Profile 2, Profile 3.
Duration:
Press <◄>, <►> can set the timeline of time history: 1min, 2min, 10min.
4.3.9 Octave
Menu of Octave can set filter
before octave calculation and the
alarm threshold of each octave
band, LAeq, LBeq, LCeq, LZeq. If
the measurement result exceeds
the threshold, the LED indicator
will turn red. Press <◄>, <►> can set the option to 0.1dB~199.9dB.
4.3.10 Custom Measure
There are 14 items in menu of
Custom Measure which can set
the parameters of group 1~14
custom measurement. Press <▲>,
< ▼ > can choose and select,
press  to access next
level of menu.

40

BSWA 308/309

BSWA Technology Co., Ltd
Press <▲>, <▼> can set the option of each group of custom
measurement: Filter, Detector and Mode.

Filter:
Press <◄>, <►> can set the filter of custom measurement: A, B, C and Z (Flat).
Detector:
Press <◄>, <►> can set the detector of custom measurement: Fast, Slow and Imp..
Mode:
Press <◄>, <►> can set the integral mode of custom measurement: SPL, SD, SEL, E,
Max, Min, Peak, LEQ, LN1~LN10.
4.3.11 Timer
Menu of Timer can set the Timer, Start Day, Start Time and
Repeat Interval. Press <▲>, <▼> can choose and select.
A new function named Timer was introduced to start
measurement by program. User can set the measurement
start from 00:00 of next day, measure several minutes and
repeat each hour, in order to achieve 24h auto measurement.
Timer:
Press <▲>, <▼> can set Timer working mode: OFF, Once and Loop.
Start Day:
Press <▲>, <▼> can set Timer trigger date: Ignore and the certain day in the future 30
days. If select Ignore, the Timer will ignore the date and only use Start Time to trigger.
Start Time:
Press <▲>, <▼> can set Timer trigger time: 00:00~23:59.
Repeat Period:
If Timer is triggered, it will be trigger all the time by the Repeat Period. Press <◄>, <►>
can set the option: 1m~59m, 1h~24h.
41

BSWA 308/309

BSWA Technology Co., Ltd

☆Note: Repeat Period must greater than total integral time (Itg.Period x Repeat) +5s,
since there is fixed 3s delay for Timer triggered measurement and another 2s is needed
before the delay. It is forbidden to change the settings when the Timer is working. Otherwise,
there will be something wrong with the Timer.
4.3.12 24h Measurement by Timer
User can use the Timer to implement 24-hour-measurement. Following description show an
example of how to implement the 24-hour -measurement.
Purpose: The measurement will be first start at 2015/3/14
00:00, measure first 5m of each hour. It will store CSD file
when the stop measurement and store SWN file every second.
Delay setting in the MEAS.Setup will be ignored if the
measurement is triggered by Timer. Set Itg.Period as 5m and
set Repeat as 1. Enable the SWN Logger and CSD Logger.
Set the SWN Log.Step to 1s and set the CSD Log.Step to 5min.
Set the Timer work at Loop mode,
so that the measurement will be
triggering all the time.
Set the Start Day as the wanted
date.

Set the Start Time to 00:00 which
means

the

first

time

of

measurement to be triggered.
Set the Repeat Interval to 1h, so
that the measurement will be
triggering each hour.

42

BSWA 308/309

BSWA Technology Co., Ltd

4.4 Setup
Menu of Setup include the basic
function

setup

and

condition

display. Press <▲>, <▼> can
choose and select, press 
to access next level menu.

4.4.1 Contrast
Menu of Contrast can set the contrast of LCD display for 14
levels adjustable. Press <▲>, <▼> can choose and select.

4.4.2 Backlight
Sound level meter provide the auto turn off function of
backlight to reduce the power consume and extend battery life.
Menu of Backlight can set the backlight timeout on-off and
delay time. Press <▲>, <▼> can choose and select.

4.4.3 Battery
Menu of Battery display the
power state and power voltage.
The discharge cut-off voltage of
single cell LR6/AA/AM3 alkaline
battery is approx. 0.9V, therefore
sound level meter will power off
automatically when the total voltage of 4 cell alkaline battery falls below 3.6V.

43

BSWA 308/309

BSWA Technology Co., Ltd

4.4.4 Trigger
Menu of Trigger can set the function of trigger on-off. Trigger
is an analog input which remote control the sound level meter
to start or stop the measurement. The trigger input located on
the bottom of sound level meter as a 3.5mm connector.

Short the signal lines and ground to trigger measurement to start, otherwise to stop the
measurement. Notice that when enable the Trigger function, the  button is
unavailable.
4.4.5 Date & Time
Menu of Date & Time can set the RTC time of sound level
meter. Press <▲>, <▼> can choose and select.

Press <▲>, <▼> can select date
format and turn to date setting.
Press <◄>, <►> can choose
year, month and day, press <▲>,
<▼> can modify the value. Press
 to save the setting.
44

BSWA 308/309

BSWA Technology Co., Ltd
The operation of time setting is almost the same. Press <◄>,
<►> can select hour, minute and second, press <▲>, <▼>
can modify the value. Press  to save the setting.
The power supply for RTC comes from an internal battery.
Please replace the RTC battery when sound level meter
cannot keep the date and time due to voltage of RTC battery is

too low. How to replace RTC battery: remove the 5 screws on the backside of sound level
meter to open the cover. The RTC battery is located on the surface of PCB as the following
figure. The model of battery is CR-1220.

☆Note: The RTC of sound level meter has calibrated to a reference clock with average error
2ppm (maximum error 3ppm). The time accuracy keep <10ppm (<26s within 30 days) at
room temperature. The maximum time error is approx. 5s~8s at 25℃ in internal test.
The RTC accuracy may vary by the
temperature due to no temperature
compensation. As the figure show the
typical temperature curve, the RTC
keep its basic frequency. When the
temperature increase or decrease,
RTC frequency change according to
-0.04ppm/ ℃ 2. Therefore, when the
temperature is 0℃, the change value
of RTC is -0.04 x (0-25)2 = -25ppm,
45

BSWA 308/309

BSWA Technology Co., Ltd

equal to slow 2.16s daily. when the temperature is 40℃, the change value of RTC is -0.04 x
(40-25)2 = -9ppm, equal to slow 0.78s daily.
The maximum error (<10ppm) given by user manual can be calculated as approx. 16℃
difference to reference temperature (25℃). Therefore, the RTC can keep every 30 day the
error <26s at 9℃~41℃ which can be recognized as room temperature. Notice that the real
RTC error may beyond the value shown in user manual if exceed the temperature range.
4.4.6 Auto PWR Off
Sound level meter provide the auto power off function to
reduce the power consume. When sound level meter keep
stop state and no key press for a while, it will power off base on
the setting. The Auto PWR Off option: 1min, 5min, 10min,
30min, Off. Press <◄>, <►> can choose and select, press
 to save the setting.
4.4.7 RS-232
Menu of RS-232 can set the option of serial port, refer to 5.
RS-232 Communication Protocol to earn more detail.

RS-232 Mode:
RS-232 Mode option：Remote, Printer. Press <◄>, <►> can choose. Sound level
meter can be control and send out data via RS-232 port at Remote mode. And RS-232
can be used to connect thermal printer (option) at Printer mode.
ID Setup:
ID Setup (refer to 5.2.2 Device ID to earn more detail) can set the ID number which is
used to distinguish among a network of more than one sound level meter. The ID can be
set as: 1~255. Press <◄>, <►> can choose and select.
Baud Rate:
Baud Rate (refer to 5.1 Hardware Configuration and Settings of Interface to earn more
46

BSWA 308/309

BSWA Technology Co., Ltd

detail) can set the communication baud rate of RS-232, the option is: 4800bps, 9600bps,
19200bps. Press <◄>, <►> can choose and select.
Flow Control:
Flow Control (refer to 5.2.7 Flow Control to earn more detail) can set the flow control
mode under remote control, the option is: Software, Hardware. Press <◄>, <►> can
choose and select.
Response:
Response (refer to 5.3 Instruction to earn more detail) can enable or disable the
response signal (ACK/NAK), the option is: ON, OFF. Press <◄>, <►> can choose and
select.
4.4.8 File Manager
File Manager can manage the stored SWN, OCT and CSD file.
The numbers display at the right side of each line is the file
count for each kind of file type. Press <▲>, <▼> can choose
and select, press  to access next level of menu.

Menu of SWN File can delate
SWN files, press <▲>, <▼> to
select the file number which want
to be delete. The whole file name
will be display on the bottom of
the screen. Select 0000 as the file
number can delete the entire existing SWN file.
Menu of OCT File can delete the
OCT file. The operation is same to
menu of SWN File.

47

BSWA 308/309

BSWA Technology Co., Ltd
Menu of CSD File can view, print
and delete the CSD file. Press
<▲>, <▼> can change the cursor
between Select and Option.
Delete operation is same to menu
of SWN File.
Select Option in menu of CSD
File, and then press <◄>、<►>
can View or Print the CSD file.
After select file number and action,
press  to view or print the
content of file.
Press <▲>, <▼>, <◄>, <►> can
brown file contents at View mode.
The Print mode is almost same to
View mode. Press  can
print the current displayed content
of CSD file.

4.4.9 Boot Mode
In menu of Boot Mode, press<▲>, <▼> can select Normal,
Power & Boot, Boot & Auto Meas. mode.
☆Note: The hardware mode switch located in the battery
compartment need to be set to fit to different boot mode.

Normal:
Need to change hardware mode switch to Normal. This is the normal working mode of
sound level meter.
Power & Boot:
Need to change hardware mode switch to Boot. After select this mode, sound level
48

BSWA 308/309

BSWA Technology Co., Ltd

meter will power on when proper power supply available. It’s suitable for integrate into
other system, especially in those cases where power failure, sound level meter can
power on automatically from power shutdown.
Boot & Auto Meas.:
Need to change hardware mode switch to Boot. After select this mode, sound level
meter will not only power on when proper power supply available, but also start
measurement. When sound level meter was integrated into other system, it will power on
and start measurement automatically from power failure.
Hardware Mode Switch:
The hardware mode switch located in the battery compartment. It’s easily to be found
after remove the batteries. Please select the switch to Boot or Normal by nib or tweezers.

☆Note: Static electricity sensitive area. Eliminate static electricity before
operation.
4.4.10 USB Mode
Menu of USB Mode can set the working mode when connect
sound level meter to computer by USB cable. Always Ask,
USB Disk Mode and Modem Mode can be select.

Always Ask:
It always ask which mode should apply when connect to computer by USB. Please make
choose in time, otherwise computer could not recognize the sound level meter due to
49

BSWA 308/309

BSWA Technology Co., Ltd

timeout.
USB Disk Mode:
It always working at USB Disk Mode without ask when connect to computer by USB.
Sound level meter can be recognized as removable USB disk by computer without driver
install, and the files stored in MicroSD card can be access by explorer directly.
Modem Mode:
It always working at Modem Mode without ask when connect to computer by USB.
Sound level meter can be recognized as serial port (virtual serial port) by computer and
follow the same protocol as RS-232 (refer to 5. RS-232 Communication Protocol to earn
more detail of protocol).
4.4.11 GPS
Menu of GPS can set the GPS and Auto Time Sync on-off.
When GPS is turn off, the internal GPS module is shutdown. If
enable Auto Time Sync, the RTC of sound level meter will be
synchronized

when

get

GPS

time

and

then

keep

synchronization once per hour.

4.4.12 Setup Template
The Setup Template is used to store 5 group user setting
parameter of sound level meter for different application.
☆Note: Template will not touch the Cal.Factor. Please do not
try to load the old version template in new version firmware
due to some modification could be apply in template format.

Press  on blank template
can save 1 group setting which
user can define the name by 5
letter or number.
Press  on one existing
template can load or delete it.
50

BSWA 308/309

BSWA Technology Co., Ltd

4.4.13 About
About menu shows the Type, Class, S/N (serial number), Ver.,
and HWID (hardware ID) of sound level meter.

4.5 Language
Sound level meter support 6 language: English, Chinese,
Portuguese, Spanish, German and French. Press <▲>, <▼>
can select appropriate language and press  to save
the setting.

4.6 Output
Menu of Output can select which measurement data should
be output at DC OUT. There are Level Meter DC Out and
Octave DC Out option for level meter mode and 1/1 octave
mode. The Printer option also be include in this menu. Press
<▲>, <▼> can choose and select.

4.6.1 AC OUT
There are two analog output ports on sound level meter: DC OUT and AC OUT. Please use
coaxial cable to connect DC OUT, AC OUT to other device or system. Recommend input
resistance of terminal device or system should above 5kΩ.
AC OUT port is located on the bottom of sound level meter. It output the signal of microphone
directly without and setting can be apply. The maximum output voltage is 5Vrms (±7Vpeak),
and maximum output current is ±15mA.
☆Note: Please add impedance transformation circuit when input resistance of terminal
device or system is not so high enough. AC OUT is only can be used for noise recording or
51

BSWA 308/309

BSWA Technology Co., Ltd

monitor due to noise floor is higher than the lower limit of linear range of sound level meter.
4.6.2 DC OUT
DC OUT is used to output the analog DC signal which is proportional to measurement result
with 10mV/dB ratio. For example, it output 938mV for 93.8dB. Recommend to filter or
average the output signal to remove noise.
Level Meter DC Out can set the signal output of level meter
mode. Press <▲>, <▼>, <◄>, <►> can choose and select.
Filter: A, B, C, Z (Flat)
Detector: Fast, Slow, Imp.
Mode: SPL, LEQ, Peak

Octave DC Out can set the signal output of octave mode. The
option is: LAeq, LBeq, LCeq, LZeq and 6.3Hz~20kHz. Press
<◄>, <►> can choose and select. If select unavailable band
for current function, it will display “Invalid Octave Band!”.

4.6.3 Printer
Print Option can set the printer
option to Auto or Manual. Select
Auto will print measurement result
automatically

after

stopped

measurement.

If user selects Manual option,
select

Print

Now

and

press

 to print measurement
data.

52

BSWA 308/309

BSWA Technology Co., Ltd

☆Note: Please set to Printer mode in RS-232 menu before print operation.

4.7 Factory Settings
Factory Settings provides the function for reset all the
parameters which has been modify by users. The parameters
will be initialized to the default value. Press <◄>, <►> can
select Y (Yes) or N (No). Choose Y and pressing  will
initialize the parameter. Choose N or press  will cancel
the reset.

53

BSWA 308/309

BSWA Technology Co., Ltd

5. RS-232 Communication Protocol
The Sound Level Meter BSWA 308/309 has an RS-232 serial interface. User can modify the
configuration of the sound level meter via a serial interface and control the sound level meter
to run and to stop, and get the current measurement parameters and results for further
processing. Operation via serial interface does not affect keyboard operation.

5.1 Hardware Configuration and Settings of Interface
BSWA 308/309 uses three-wire serial interface, the physical socket is PS/2-6 pins. Below is
the definition of RS-232 interface:

6

5

4

3
2

1

1.
2.
3.
4.
5.
6.

NC
GND
NC
TXD
NC
RXD

RS-232 transfer settings:
Transfer Mode

Full-duplex

Synchronous / Asynchronous Mode

Asynchronous transfer

Baudrate

4800 bps, 9600 bps, 19200 bps

Data Bits

8 bit

Stop Bits

1 bit

Parity

None

Flow Control

Follow the time data in the rated parameters table

☆Note: RS-232 connector housing should be grounded and recommended to use ground
shield wire. Please be sure to use quality and reliable RS-232 to RS-485 adaptor.

5.2 Transfer Protocol
BSWA 308/309 RS-232 interface protocol is based on a block transfer, as shown below:

Send command block

Send response block
54

BSWA 308/309

BSWA Technology Co., Ltd

A typical command block or response block consists of “starting character, ID, attribute
character, command or data, end character, block check character, carriage returns, line
feeds”, as shown below:


ID

ATTR

Command or Data



BCC





5.2.1 Start/Stop of the Block Transfer
A command block or response block contains start characters, end characters and other
control character as shown below:
Name

Hex

Meaning



02H

Start Character



03H

Stop Character



0DH

Carriage Returns



0AH

Line Feeds

5.2.2 Device ID
Each command block contains an ID. It is used to distinguish among a network of more than
one sound level meter. When the sound level meter receives a command block, it will match
the ID contained in the command block and its own ID. If matched, the corresponding
operation will be performed. If not, then ignore this command. The response block returned
from the sound level meter also contains the ID which is used to indicate that the block is sent
by which one.
☆Note: Please ensure that the ID of sound level meter in the same network are different
from each other, otherwise the error will occur during operation!
ID is one byte of binary. It ranges from 1~255.The corresponding hex value is 01H~FFH.
It means that the command is a broadcast command if the ID contained in command block is
00H. The sound level meter will execute the instruction without any return data, regardless of
its own ID when the command is a broadcast command.
Name

Hex

Meaning

01H~FFH

Device ID

00H

Broadcast Command

ID
5.2.3 ATTR Attribute Character
ATTR attribute characters indicate the type of command or response.
55

BSWA 308/309

BSWA Technology Co., Ltd

Name

Hex

Meaning

‘C’

43H

Command Block

‘A’

41H

Response Block



06H

Normal Response



15H

Error Response

5.2.4 BCC (Block Check Character)
BCC check bit which include in block is calculated by the sender. The receiver can calculate
the block’s BCC value and will compare with the BCC value contained in the send block. If
same, it indicates that the received block is correct. BCC value is calculated by using bytes
between  and  with XOR operation. Sound level meter will not verify operation
and directly authorized instruction if BCC is 00H.This way you can simplify the sending of the
instruction block, but do not recommend this way for long-distance applications, because the
BCC is the only way to guarantee reliability of data transmission.
Name

Hex

Meaning

01H~FFH

XOR Checksum

00H

Ignore the Checksum

BCC
5.2.5 Block Transfer Format
Block transfer of data have four types: command block, response block, normal response
block and error response block. The following were to describe the four types of instruction
format.
(1) Command Block: sent by the computer.


ID

ATTR

Instruction

Parameter



BCC





1

1

1

3

N

1

1

1

1

Byte

Where: ATTR=’C’.
All instructions occupy 3 bytes. If more than one parameter included, all parameters should
be separated by spaces.
(2) Response Block: sent by the sound level meter.


ID

ATTR

Response



BCC





1

1

1

N

1

1

1

1

56

Byte

BSWA 308/309

BSWA Technology Co., Ltd

Where: ATTR=’A’.
If more than one response data, each data should be separated by a comma ‘,’.
(3) Normal Response: sent by the sound level meter.


ID

ATTR



BCC





1

1

1

1

1

1

1

Byte

Where: ATTR=。
(4) Error Response: sent by the sound level meter


ID

ATTR

Error code



BCC





1

1

1

4

1

1

1

1

Byte

Where: ATTR=.
The error code occupies 4 bytes. All possible error code is listed in the following table. The
meaning of error code is described in section 5.2.6.
Error Code

Meaning

0001H

Instruction Error

0002H

Parameter Error

0003H

Unavailable on the Current State

5.2.6 Recovery from Transmission Errors
Various errors may occur when transfer the command block or response block. The following
describe how the sound level meter will deal with and restore to the initial state when an error
occurs.
(1) Block Transfer Not Complete
Section 5.2.5 describes the 4 kinds of block transmission format. When the sound level meter
receives the beginning of a block of characters , it will continue to receive the
remaining data until the end of the block , . When the data reception is complete
and correct parity, the sound level meter will conduct follow-up actions. If received the
character  again before , , the sound level meter will ignore all the
information previously received and re-start the reception of a block.
(2) Validation Failure
After receiving the data block, sound level meter will verify it (except when BCC=00H). When
validation fails, the sound level meter will ignore this instruction.
57

BSWA 308/309

BSWA Technology Co., Ltd

(3) Instruction Error
The sound level meter may not recognize the instruction received due to the computer sends
an undefined instruction, or unexpected error has occurred during transmission. When the
above errors occur, the sound level meter will return a NAK block, which contains the error
code 0001H.
(4) Parameter Error
Parameters include in command block also could be wrong due to the parameters not
separate by a space, over the available range, or an incorrect number of arguments. When
the above error occurs, the sound level meter will return NAK block, which contains the
error-code 0002H.
(5) Unavailable on the Current State
The current state cannot make the appropriate operating when the following happens:
Be request to return octave data in level meter mode, or be request to return level
1
meter data in octave mode.
2

Be request to perform the calibration operation when running the measurement.
Be request to change the measurement parameters or system parameters when

3
running the measurement.
When the above error occurs, the sound level meter will return NAK block, which contains the
error-code 0003H.
5.2.7 Flow Control
The sound level meter uses three-wire serial interface by P/S2-6 pin socket, which doesn’t
contain the hardware flow control pins. Sound level meter doesn’t support software flow
control. Operation along to the requirements of the rated section 5.2.9 Rated Parameters can
guarantee the correctness of the send data and receive data.
5.2.8 Multi-Machine Operation
More than one sound level meter can be connected to the RS-232 bus, to form a
measurement network. Users can change the setting of all sound level meter in same
network through broadcast instruction, or access to data and parameters of an each sound
level meter by ordinary instruction.
Need to pay attention:
58

BSWA 308/309

BSWA Technology Co., Ltd

(1) Ensure that no same ID of sound level meter in each network.
(2) User cannot broadcast command which can return any data.
5.2.9 Rated Parameters
Name
Response time of

Min.

Rated

Max.

—

—

2s

Description
Time-out processing should be

sound level meter

operating when the value exceeds.

Time interval of
instruction sending to

—

100ms

—

—

sound level meter
Waiting time after
received  for

Means that the sound level meter
—

Unlimited

—

sound level meter

will waiting for the remaining data
forever.

Time interval between
each byte for sound

—

Unlimited

—

Means that the sending speed of
the computer could be very slow.

level meter to receive

5.3 Instruction
The instruction has two types: set instructions and query instructions.
Set Instructions: Set the measurement parameters and system parameters of sound level
meter.
Query Instructions: Query the parameters and data of the sound level meter.
There are 3 kind of situation for sending instruction to sound level meter: set instruction (no
response), set instructions (with response), query instructions.
(1) Set Instruction (no response):
Set Instruction

—►

Sound Level

Computer
Meter
(2) Set instructions (with response):
Normal response:
Set Instruction
Computer

◄—

Return ACK

—►

Sound Level
Meter

59

BSWA 308/309

BSWA Technology Co., Ltd

Error response:
Set Instruction
Computer

◄—

—►

Sound Level
Meter

Return NAK

(3) Query command:
Normal response:
Query Instruction
Computer

◄—

—►

Sound Level
Meter

Return Data

Error response:
Query Instruction
Computer

60

◄—

Return NAK

—►

Sound Level
Meter

BSWA 308/309

BSWA Technology Co., Ltd

5.3.1 Instruction List
IDXp1: Setup ID ............................................................................................................ 65
IDX?: Query ID ............................................................................................................. 65
BRTp1: Set the RS-232 Baud Rate ............................................................................... 66
BRT?: Query The RS-232 Baud Rate Setting ................................................................ 66
XONp1: Set the Flow Control ....................................................................................... 67
XON?: Query Flow Control Setting ................................................................................ 67
RETp1: Set Response Mode......................................................................................... 67
RET?: Query Response Mode Setting........................................................................... 68
MEMp1: Set the Measurement Mode ............................................................................ 68
MEM?: Query Measurement Mode Setting .................................................................... 69
CALp1: Set Calibration Level and Calibrate by Measurement ........................................ 69
CAL?: Query Calibration Level and Calibration Factor ................................................... 70
CAFp1: Calibrate by Calibration Factor ......................................................................... 70
CAF?: Query Calibration History ................................................................................... 70
BSEp1_p2_p3_p4_p5_p6_p7: Measurement Setup ...................................................... 71
BSE?: Query Measurement Setup ................................................................................ 72
RNS?: Query Measurement Range ............................................................................... 72
ICPp1: Set ICCP Power ................................................................................................ 73
ICP?: Query ICCP Power State..................................................................................... 73
PR1p1_p2_p3_p4：Set Profile1 ................................................................................... 73
PR1?: Query Profile1 Setting ........................................................................................ 74
PR2p1_p2_p3_p4: Set Profile2 ..................................................................................... 74
PR2?: Query Profile2 Setting ........................................................................................ 74
PR3p1_p2_p3_p4: Set Profile3 ..................................................................................... 74
PR3?: Query Profile3 Setting ........................................................................................ 74
ALMp1: Set Alarm Threshold ........................................................................................ 75
ALM?: Query the Alarm Threshold Setting..................................................................... 75
ETFp1_p2_p3_p4_p5: Set Extended Function .............................................................. 75
ETF?: Query Extended Function Setting ....................................................................... 76
61

BSWA 308/309

BSWA Technology Co., Ltd

STSp1_p2_p3……p11_p12: Set Statistical ................................................................... 76
STS?: Query Statistical ................................................................................................. 77
HISp1_p2: Set Time History .......................................................................................... 77
HIS?: Query Time History Setting.................................................................................. 78
OCSp1_p2……p13_p14: Set Octave Threshold ............................................................ 78
OCS?: Query Octave Threshold Setting ........................................................................ 79
CUSp1_p2_p3_p4: Set Custom Measure .................................................................... 80
CUSp1_?: Query Custom Measure Setting ................................................................... 81
TISp1_p2_p3_p4_p5: Set Timer.................................................................................... 81
TIS?: Query Timer Setting............................................................................................. 82
CONp1: Set Contrast .................................................................................................. 82
CON?: Query Contrast Setting ...................................................................................... 82
BLTp1_p2: Set Backlight ............................................................................................. 83
BLT?: Query Backlight Setting....................................................................................... 83
BAT?: Query Battery State .......................................................................................... 83
TRGp1: Set Trigger ..................................................................................................... 84
TRG?: Query Trigger Setting ....................................................................................... 84
DATp1_p2_p3_p4: Set Date ........................................................................................ 85
DAT?：Query Date Setting ........................................................................................... 85
HORp1_p2_p3: Set Time ............................................................................................ 85
HOR?: Query Time Setting .......................................................................................... 86
PWOp1: Set Auto Power Off ........................................................................................ 86
PWO?: Query Auto Power Off Setting.......................................................................... 86
OPMp1: Set Boot Mode............................................................................................... 87
OPM?: Query Boot Mode Setting................................................................................. 87
UMDp1: Set USB Mode ................................................................................................ 88
UMD?: Query USB Mode Setting .................................................................................. 88
GPDp1_p2: Set GPS .................................................................................................... 88
GPD?: Query GPS Setting .......................................................................................... 89
VER?: Query About Information................................................................................... 89
62

BSWA 308/309

BSWA Technology Co., Ltd

LNGp1: Set Language ................................................................................................. 89
LNG?: Query Language Setting................................................................................... 90
OUTp1_p2_p3_p4: Set Output .................................................................................... 90
OUT?: Query Output Setting ....................................................................................... 91
RES: Apply Factory Settings ......................................................................................... 91
STAp1: Start / Stop Measurement ............................................................................... 91
STA?: Query Measurement State ................................................................................ 92
DMAp1_?: Query the Main Screen Data ...................................................................... 92
TPRp1_?: Query 3-Profile Screen Data ....................................................................... 93
DLNp1_?: Query Statistical Analysis Data (LN) ............................................................ 93
DCU?: Query Custom Measure Data ........................................................................... 94
DSLp1_p2_?: Query All the Data of the Sound Level Meter ......................................... 95
DOT?: Query Octave Data .......................................................................................... 96
CSD: Save Custom Data into MicroSD ........................................................................ 97

63

BSWA 308/309

BSWA Technology Co., Ltd

5.3.2 Instruction Format
In this section, “☐☐☐” on behalf of the 3 characters of the instruction, “p1, p2 ......” on behalf
of the parameter “d1, d2 ...” means the data, “_” means a space.
(1) Separate The Parameters By Space For Multiple Parameters In One Instruction:
☐☐☐

Instruction without parameters

☐☐☐p1

Instruction with 1 parameter

☐☐☐p1_p2

Instruction with 2 parameters

☐☐☐?

Instruction with query parameter

☐☐☐p1_?

Instruction with 1 parameter and a query parameter

☐☐☐p1_ p2_?

Instruction with 2 parameters and a query parameter

The parameters can be a wide range, for example from 1 to 255. These parameters are
sending by the format of ASCII. Therefore, you may need to send 1~3 bytes.
☐☐☐93

Parameter is 93

☐☐☐124

Parameter is 124

Note that both of 93 and 124 are single parameter. So the individual numbers don’t need
to be separated by spaces.
☐☐☐1_64

2 individual parameters, 1 and 64

Note that 1 and 64 are two parameters in one instruction. So those parameters need to
be separated by space.
The parameter is possible to be decimal or integer type. However, if the actual value is
integer type, decimal point and decimal bits can be omitted.
(2) Separate The Data By Comma For Multiple Data In One Response
d1,d2,d3

Return 3 data

Response block, the data bits actually returned is less than its maximum possible
number of digits, leading zeros. For example, return 2 data with the maximum possible
value 255 (3 digits), and the actually data is 76 and 9, the response is:
076,009

Return data 76 and 9

If the returned data contains date and time, use the slash “/” to separate data and use the
colon “:” to separate the time:
2011/08/05，12:13:55
64

BSWA 308/309

BSWA Technology Co., Ltd

5.3.3 Instruction Describe
Note in This Section:
 In the following description, the value, range and default value of parameter are show as
ASCII code.
 The default value means the sound level meter just delivery to user or restore to the
factory settings.

IDXp1: Setup ID
ID of sound level meters in one network must be different. Otherwise, there will be a
communication error.
☆Note: When the IDX instruction is correctly received by sound level meter, ACK signal will
be returned with the new ID.
Instruction

Parameters
p1: ID number;

Explanation

IDX

Range: 1~255;
Default: 1

ASCII

I

D

X

1

Hex

49H

44H

58H

31H

Byte

1

1

1

1~3

Return

ACK / NAK

Example 1: set the ID as 3.
02 01 43 49 44 58 33 03 25 0D 0A
Return: ACK. Note where ID has been changed to 3 (03H).
02 03 06 03 040D 0A
Example 2: set the ID as 255.
02 01 43 49 44 58 32 35 35 03 24 0D 0A
Return: ACK. Note where ID has been changed to 255 (FFH).
02 FF 06 03 F8 0D 0A

IDX?: Query ID
Explanation

Instruction

Parameters

IDX

Query parameter: ?

ASCII

I

D

X

?

Hex

49H

44H

58H

3FH

Byte

1

1

1

1

Return

Return the current ID number
65

BSWA 308/309

BSWA Technology Co., Ltd

Example: query ID.
02 01 43 49 44 58 3F 03 29 0D 0A
Return: the current ID 001.
02 01 41 30 30 31 03 70 0D 0A

BRTp1: Set the RS-232 Baud Rate
☆Note: When the BRT instruction is correctly received by the sound level meter, it will return
the ACK by previous baud rate, and then update the baud rate.
Instruction

Parameters
p1: RS-232 baud rate;
2=4800bps;

Explanation

BRT

3=9600bps;
4=19200bps;
Default: 3

ASCII

B

R

T

3

Hex

42H

52H

54H

33H

Byte

1

1

1

1

Return

ACK / NAK

Example: set the baud rate to 9600bps.
02 01 43 42 52 54 33 03 34 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

BRT?: Query The RS-232 Baud Rate Setting
Instruction

Parameters

BRT

Query parameter: ?

Explanation
ASCII

B

R

T

?

Hex

42H

52H

54H

3FH

Byte

1

1

1

1

Return
Example: query the current baud rate.
02 01 43 42 52 54 3F 03 38 0D 0A
Return: the current baud rate is 9600bps.
02 01 41 33 03 72 0D 0A

66

Return the current baud rate

BSWA 308/309

BSWA Technology Co., Ltd

XONp1: Set the Flow Control
Instruction

Parameters
p1: Flow control mode;

Explanation

0=Hardware flow control;

XON

1=Software flow control;
Default: 1

ASCII

X

O

N

1

Hex

58H

4FH

4EH

31H

Byte

1

1

1

1

Return

ACK / NAK

Example: set to software flow control mode.
02 01 43 58 4F 4E 31 03 2B 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

XON?: Query Flow Control Setting
Instruction

Parameters

XON

Query parameter: ?

Explanation
ASCII

X

O

N

?

Hex

58H

4FH

4EH

3FH

Byte

1

1

1

1

Return

Return flow control mode

Example: query flow control mode.
02 01 43 58 4F 4E 3F 03 25 0D 0A
Return: the current flow control mode is software flow control.
02 01 41 31 03 70 0D 0A

RETp1: Set Response Mode
Response means the ACK / NAK signal returned from the sound level meter (HIS and OCS
instruction returns MicroSD card state or NAK).User can enable or disable such a response.
☆Note: RET instruction itself is not affected by response mode. When the sound level meter
receive the RET instruction, it will return ACK/NAK whether the current state is enabled or
disabled. RET? Query command is also not subject to the influence of response mode.
Instruction

Parameters
p1: Response mode;

Explanation

RET

0=Disabled;
1=Enabled;
67

BSWA 308/309

BSWA Technology Co., Ltd
Default: 1

ASCII

R

E

T

1

Hex

52H

45H

54H

31H

Byte

1

1

1

1

Return

ACK / NAK

Example: set to enable response.
02 01 43 52 45 54 31 03 31 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

RET?: Query Response Mode Setting
Instruction

Parameters

RET

Query parameter: ?

Explanation
ASCII

R

E

T

?

Hex

52H

45H

54H

3FH

Byte

1

1

1

1

Return

Return response mode

Example: query response mode.
02 01 43 52 45 54 3F 03 3F 0D 0A
Return: the current response mode is to enable the response.
02 01 41 31 03 70 0D 0A

MEMp1: Set the Measurement Mode
When MEM instruction is correctly received by the sound level meter, it will switch to the main
screen of the octave mode or the main screen of level meter mode according to the
corresponding parameter in instruction.
☆Note: The 1/3 octave band is optional function.
Instruction

Parameters
p1: Measurement mode;
0=1/1Octave;

Explanation

MEM

1=Level meter mode;
2=1/3 Octave (Optional);
Default: 1

ASCII

M

E

M

1

Hex

4DH

45H

4DH

31H

Byte

1

1

1

1

Return
68

ACK / NAK

BSWA 308/309

BSWA Technology Co., Ltd

Example: set the sound level meter mode.
02 01 43 4D 45 4D 31 03 37 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

MEM?: Query Measurement Mode Setting
Instruction

Parameters

MEM

Query parameter: ?

Explanation
ASCII

M

E

M

?

Hex

4DH

45H

4DH

3FH

Byte

1

1

1

1

Return

Return the measurement mode

Example: query the measurement mode.
02 01 43 4D 45 4D 3F 03 39 0D 0A
Returns: the current measurement mode is level meter mode.
02 01 41 31 03 70 0D 0A

CALp1: Set Calibration Level and Calibrate by Measurement
☆Note: When CAL instruction is correctly received by the sound level meter, two ACK will be
returned at the beginning and the end of the calibration (several seconds will be spent by the
calibration). In the calibration history, ending with symbol M indicate the record was calibrate
by the method of by Measurement.
Instruction

Parameters
p1: Calibration level;

Explanation

CAL

Range: 0~199.9;
Default: 93.8

ASCII

C

A

L

93.8

Hex

43H

41H

4CH

39H，33H，2EH，38H

Byte

1

1

1

1~5

Return

ACK / NAK

Example 1: set the calibration level as 94dB and calibrate by measurement.
02 01 43 43 41 4C 39 34 03 00 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A
Return again after calibration finished: ACK
02 01 06 03 06 0D 0A
Example 2: set the calibration level as 113.8dB and calibrate by measurement.
69

BSWA 308/309

BSWA Technology Co., Ltd

02 01 43 43 41 4C 31 31 33 2E 38 03 28 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A
Return again after calibration finished: ACK
02 01 06 03 06 0D 0A

CAL?: Query Calibration Level and Calibration Factor
Instruction

Parameters

MEM

Query parameter: ?

Explanation
ASCII

C

A

L

?

Hex

43H

41H

4CH

3FH

Byte

1

1

1

1

Return

Return the value of the calibration level and calibration factor

Example: query the calibration level and calibration factor.
02 01 43 43 41 4C 3F 03 32 0D 0A
Return: the current calibration level is 094.0dB, the calibration factor is 000.00dB.
02 01 41 30 39 34 2E 30 2C 2B 30 30 30 2E 30 30 03 7B 0D 0A

CAFp1: Calibrate by Calibration Factor
This instruction can modify the calibration factor. In the calibration history, code “F” at the end
of each line means by calibration factor.
Instruction

Parameters
p1: Calibration factor;

Explanation

Range: -199.99~+199.99 (“+”

CAF

sign can be omitted);
Default: 0

ASCII

C

A

F

0

Hex

43H

41H

46H

30H

Byte

1

1

1

1~7

Return

ACK / NAK

Example: set the calibration factor value as 0.74dB (“+” sign is omitted).
02 01 43 43 41 46 30 2E 37 34 03 1A 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

CAF?: Query Calibration History
Query the most recent 4 group history of calibration.
70

BSWA 308/309

BSWA Technology Co., Ltd
Instruction

Parameters

CAF

Query parameter: ?

Explanation
ASCII

C

A

F

?

Hex

43H

41H

46H

3FH

1

1

1

1

Byte

Returns the most recent 4 group history of calibration.
Format “Year/Month/day, hour:minute:second, calibration factor, code”.

Return

Code: M=By Measurement, F=By Calibration Factor.
Example: query the calibration history.
02 01 43 43 41 46 3F 03 38 0D 0A
Return: the data returned by this instruction use a slash “/” split date, use a colon “,” split time.
Calibration history is 2011/08/04, 17:03:28, +001.29, F, 2011/08/04, 17:03:02, +001.25, F,
2011/08/04, 17:02:20, +000.71, F, 2011/08/04, 17:02:00, +001.27, M.
02 01 41 32 30 31 31 2F 30 38 2F 30 34 2C 31 37 3A 30 33 3A 32 38 2C 2B
30 30 31 2E 32 39 2C 46 2C 32 30 31 31 2F 30 38 2F 30 34 2C 31 37 3A 30
33 3A 30 32 2C 2B 30 30 31 2E 32 35 2C 46 2C 32 30 31 31 2F 30 38 2F 30
34 2C 31 37 3A 30 32 3A 32 30 2C 2B 30 30 30 2E 37 31 2C 46 2C 32 30 31
31 2F 30 38 2F 30 34 2C 31 37 3A 30 32 3A 30 30 2C 2B 30 30 31 2E 32 37
2C 4D 03 62 0D 0A

BSEp1_p2_p3_p4_p5_p6_p7: Measurement Setup
Set the delay, integral period, repeat, and logger setup.
Instructi

P1

on

P2

ion

P5

P6

P7

p3:

p4: SWN p5:SWN p6:CSD

p7:CSD

1~60=1~6 integral

repeat;

logger;

logger

0s;

0=Inf;

0=disable ep

0=disable step;

1~9999

;

;

period;

1m;

logger ;st logger;
0=0.1s;

1~59=1~5 =1~9999 1=enable; 1=0.2s;

62=Sync. 9s;
BSE

P4

p1: delay; p2:

61=Sync. 0=Inf;

Explanat

P3

15m;

times;

Default: 0 2=0.5s;

60~118=1 Default: 0

0~58=1~5

1=enable; 9s;
Default: 0 59~117=1

3~61=1~5

~59m;

63=Sync. ~59m;

9s;

118~141=

30m;

62~120=1

1~24h;

64=Sync. 1h~24h;

~59m;

Default:

1h;

121~144=

59

119~142=
Default: 0

Default: 1

1h~24h;
Default: 3

ASCII

B S E

1

0

0

0

3

0

59
71

BSWA 308/309
42 53 45

Hex

H H H

Byte

1 1 1

BSWA Technology Co., Ltd

31H

30H

30H

30H

33H

30H

35H, 39H

1~2

1~3

1~4

1

1~3

1

1~2

Returns:
Return 0=setting succeed, MicroSD card is OK; 1=setting succeed, but the MicroSD card is
abnormal; 2=setting succeed, but no MicroSD card detected.
Example: set delay as 2s, integral period as 5m, repeat as infinite, SWN logger enable, SWN
logger step as 0.2s, CSD logger disable, CSD logger step as 2s.
02 01 43 42 53 45 32 20 36 34 20 30 20 31 20 31 20 31 20 31 03 17 0D 0A
Returns: setting succeeds, MicroSD card is OK.
02 01 41 30 03 71 0D 0A

BSE?: Query Measurement Setup
Instruction

Parameters

BSE

Query parameter: ?

Explanation
ASCII

B

S

E

?

Hex

42H

53H

45H

3FH

1

1

1

1

Byte
Return

Return parameter of measurement setup: delay, integral period,
repeat, SWN logger, SWN logger step, CSD Logger, CSD Logger step.

Example: query the measurement setup.
02 01 43 42 53 45 3F 03 28 0D 0A
Returns: the current measurement setup: delay=2s, integral period=5min, repeat=infinite,
SWN logger=enable, SWN logger step= 0.2s, CSD logger=enable, CSD logger step=2s.
02 01 41 30 32 2C 30 36 34 2C 30 30 30 30 2C 31 2C 30 30 31 2C 31 2C 30
30 31 03 71 0D 0A

RNS?: Query Measurement Range
Instruction

Parameters

RNG

Query parameter: ?

Explanation
ASCII

R

N

S

?

Hex

52H

4EH

53H

3FH

Byte

1

1

1

1

Return

Return measurement range

Example: query measurement range.
02 01 43 52 4E 53 3F 03 33 0D 0A
Return: linearity, dynamic and peak C range is 22.8-133.8, 12.8-133.8, 44.8-136.8.
72

BSWA 308/309

BSWA Technology Co., Ltd

02 01 41 30 32 32 2E 38 7E 31 33 33 2E 38 2C 30 31 32 2E 38 7E 31 33 33
2E 38 2C 30 34 34 2E 38 7E 31 33 36 2E 38 03 38 0D 0A

ICPp1: Set ICCP Power
Instruction

Parameters
p1: ICCP power state;

Explanation

0=Enable;

ICP

1=Disable;
Default: 0

ASCII

I

C

P

0

Hex

49H

43H

50H

30H

Byte

1

1

1

1

Return

ACK / NAK

Example: enable ICCP power:
02 01 43 49 43 50 30 03 29 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

ICP?: Query ICCP Power State
Instruction

Parameters

ICP

Query parameter: ?

Explanation
ASCII

I

C

P

?

Hex

49H

43H

50H

3FH

Byte

1

1

1

1

Return

Return ICCP power state

Example: query ICCP power state
02 01 43 49 43 50 3F 03 26 0D 0A
Return: ICCP power is enable
02 01 41 30 03 71 0D 0A

PR1p1_p2_p3_p4：Set Profile1
Instruction

Explanation

PR1

P1

P2

P3

P4

p1:

p2:

p3:

p4:

Filter;

Detector;

Integration

SWN

0=A;

0=Fast;

mode;

Logger;

1=B;

1=Slow;

0=SPL;

0=LEQ;

2=C;

2=Imp;

1=PEAK;

1=PEAK;
73

BSWA 308/309

BSWA Technology Co., Ltd
3=Z;

Default: 0

Default: 0

2=LEQ;

2=MAX;

3=MAX;

3=MIN;

4=MIN;

Default: 0

Default: 0
ASCII

P

R

1

0

0

0

0

Hex

50H

52H

31H

30H

30H

30H

30H

Byte

1

1

1

1

1

1

1

Return

ACK / NAK

Example: set Profile1 as A, Fast, SPL and save LEQ.
02 01 43 50 52 31 30 20 30 20 30 20 30 03 50 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

PR1?: Query Profile1 Setting
Instruction

Parameters

PR1

Query parameter: ?

Explanation
ASCII

P

R

1

?

Hex

50H

52H

31H

3FH

Byte

1

1

1

1

Return

Return Profile1 setting

Example: query Profile1 setting.
02 01 43 50 52 31 3F 03 4F 0D 0A
Return: current Profile1 setting is A, Fast, SPL, save LEQ.
02 01 41 30 2C 30 2C 30 2C 30 03 6D 0D 0A

PR2p1_p2_p3_p4: Set Profile2
Except the instruction is “PR2” and the default filter is 2 (C-weighting), all others are same to
the “PR1”.

PR2?: Query Profile2 Setting
Except the instruction is “PR2”, all others are same to the “PR1?”.

PR3p1_p2_p3_p4: Set Profile3
Except the instruction is “PR3” and the default filter is 3 (Z-weighting), all others are same to
the “PR1”.

PR3?: Query Profile3 Setting
74

BSWA 308/309

BSWA Technology Co., Ltd

Except the instruction is “PR3”, all others are same to the “PR1?”.

ALMp1: Set Alarm Threshold
Instruction

Parameters
p1: Alarm threshold;

Explanation

ALM

Range: 20~200;
Default: 100

ASCII

A

L

M

100

Hex

41H

4CH

4DH

31H, 30H, 30H

Byte

1

1

1

1~3

Return

ACK / NAK

Example: setting alarm threshold as 100dB.
02 01 43 41 4C 4D 31 30 30 03 32 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

ALM?: Query the Alarm Threshold Setting
Instruction

Parameters

ALM

Query parameter: ?

Explanation
ASCII

A

L

M

?

Hex

41H

4CH

4DH

3FH

Byte

1

1

1

1

Return

Return alarm threshold

Example: query alarm threshold.
02 01 43 41 4C 4D 3F 03 3C 0D 0A
Return: the current alarm threshold is 100dB.
02 01 41 31 30 30 03 70 0D 0A

ETFp1_p2_p3_p4_p5: Set Extended Function
Instruction

Explanation

ETF

P1

P2

P3

P4

P5

p1:

p2:

p3: Time

p4:

p5: GPS

3Profile

Statistical

History

Custom

Screen;

Screen;

Screen;

Screen;

Screen;

0=Disable;

0=Disable; 0=Disable; 0=Disable; 0=Disable; 1=Enable
ASCII
Hex

E

T

F

45H 54H 46H

1=Enable

1=Enable

1=Enable

1

1

1

1=Enable
1

1

31H

31H

31H

31H

31H
75

BSWA 308/309
Byte

BSWA Technology Co., Ltd
1

1

1

1

1

Return

1

1

1

ACK / NAK

Example: enable 3Profile, statistical, time history, custom, GPS.
02 01 43 45 54 46 31 20 31 20 31 20 31 20 31 03 25 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

ETF?: Query Extended Function Setting
Instruction

Parameters

ETF

Query parameter: ?

Explanation
ASCII

E

T

F

?

Hex

45H

54H

46H

3FH

Byte

1

1

1

1

Return

Return the extended function setting

Example: query the extended function setting
02 01 43 45 54 46 3F 03 2B 0D 0A
Return: 3Profile, statistical, time history, custom and GPS are all enable
02 01 41 31 2C 31 2C 31 2C 31 2C 31 03 70 0D 0A

STSp1_p2_p3……p11_p12: Set Statistical
Instruction

Explanation

STS

P1

P2

P3~P12

p1: Filter

p2: Detector p3~p12: statistical percentage;

0=A;

0=F;

Range: 1~99;

1=B;

1=S;

Default: 10, 20, 30, 40, 50, 60,

2=C;

2=I;

70, 80, 90, 99

3=Z;

Default: 0

Default: 0
ASCII

S

T

S

0

0

10_20_30_40_50_
60_70_80_90_99
31H, 30H, 20H, 32H, 30H, 20H,
33H, 30H, 20H, 34H, 30H, 20H,

Hex

53H 54H 53H

30H

30H

35H, 30H, 20H, 35H, 30H, 20H,
36H, 30H, 20H, 37H, 30H, 20H,
38H, 30H, 20H, 39H, 30H, 20H,
39H, 39H

Byte
Return
76

1

1

1

1

1
ACK / NAK

10~20+9 (spaces)

BSWA 308/309

BSWA Technology Co., Ltd

Example: set filter as B, detector as I, percentage as 10, 20, 30, 40, 50, 60, 70, 80, 90 and 99.
02 01 43 53 54 53 31 20 32 20 31 30 20 32 30 20 33 30 20 34 30 20 35 30 20 36 30
20 37 30 20 38 30 20 39 30 20 39 39 03 35 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

STS?: Query Statistical
Instruction

Parameters

STS

Query parameter: ?

Explanation
ASCII

S

T

S

?

Hex

53H

54H

53H

3FH

Byte

1

1

1

1

Return

Return filter, detector and 10 percentage of statistical

Example: query statistical
02 01 43 53 54 53 3F 03 28 0D 0A
Return: filter=B, detector=I, percentage=10, 20, 30, 40, 50, 60, 70, 80, 90, 99.
02 01 41 31 2C 32 2C 31 30 2C 32 30 2C 33 30 2C 34 30 2C 35 30 2C 36 30
2C 37 30 2C 38 30 2C 39 30 2C 39 39 03 6F 0D 0A

HISp1_p2: Set Time History
Instruction

Explanation

Parameters 1

HIS

Parameters 2

p1: Profile;

p2: Duration;

0=Profile1;

0=1min;

1=Profile2;

1=2min;

2=Profile3;

2=10min;

Default: 1

Default: 1

ASCII

H

I

S

1

1

Hex

48H

49H

53H

31H

31H

Byte

1

1

1

1

1

Return

ACK / NAK

Example: set Profile2 as data sources and duration as 2min.
02 01 43 48 49 53 31 20 31 03 31 0D 0A
Return: ACK.
02 01 06 03 06 0D 0A

77

BSWA 308/309

BSWA Technology Co., Ltd

HIS?: Query Time History Setting
Instruction

Parameters

HIS

Query parameter: ?

Explanation
ASCII

H

I

S

?

Hex

48H

49H

53H

3FH

Byte

1

1

1

1

Return

Return time history setting

Example: query time history setting.
02 01 43 48 49 53 3F 03 2E 0D 0A
Returns: the current data sources=Profile2, duration=2min.
02 01 41 31 2C 31 03 6D 0D 0A

OCSp1_p2……p13_p14: Set Octave Setting
Instruction

Explanation

OCS

Parameter 1

Parameter 2~41

p1：Filter

p2~p41: The threshold of LeqA, LeqB,

0=Z;

LeqC, LeqZ, 6.3Hz~20kHz;

1=C;

Range: 0-199.9;

2=B;

Default: 31.5Hz=79, 63Hz=63, 125Hz=52,

3=A;

250Hz=44, others=38

Default: 0
38_38_38_38_38_38_38_38_38_38_38_79
ASCII

O

C

S

1

_38_38_63_38_38_52_38_38_44_38_38_3
8_38_38_38_38_38_38_38_38_38_38_38_
38_38_38_38_38
33H，38H，20H，33H，38H，20H，33H，
38H，20H，33H，38H，20H，33H，38H，
20H，33H，38H，20H，33H，38H，20H，
33H，38H，20H，33H，38H，20H，33H，
38H，20H，33H，38H，20H，37H，39H，
20H，33H，38H，20H，33H，38H，20H，

Hex

4FH 43H 53H

31H

36H，33H，20H，33H，38H，20H，33H，
38H，20H，35H，32H，20H，33H，38H，
20H，33H，38H，20H，34H，34H，20H，
33H，38H，20H，33H，38H，20H，33H，
38H，20H，33H，38H，20H，33H，38H，
20H，33H，38H，20H，33H，38H，20H，
33H，38H，20H，33H，38H，20H，33H，

78

BSWA 308/309

BSWA Technology Co., Ltd
38H，20H，33H，38H，20H，33H，38H，
20H，33H，38H，20H，33H，38H，20H，
33H，38H，20H，33H，38H，20H，33H，
38H，20H，33H，38H，20H，33H，38H

Byte

1

1

1

1

Return

80+39 (space)
ACK / NAK

Example: set Filter as C-weighting; all the threshold values are 38.
02 01 43 4F 43 53 31 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33
38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33
38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33
38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33
38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 20 33 38 03 00 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

OCS?: Query Octave Setting
Instruction

Parameters

OCS

Query parameter: ?

Explanation
ASCII

O

C

S

?

Hex

4FH

43H

53H

3FH

Byte

1

1

1

1

Return

Return octave setting

Example: query octave setting.
02 01 43 4F 43 53 3F 03 23 0D 0A
Returns: return Filter and threshold of LeqA, LeqB, LeqC, LeqZ, 6.3Hz~20kHz. For example:
Filter is C-weighting, threshold are LeqA=038.1；LeqB=038.2；LeqC=038.3；LeqZ=038.4；
6.3Hz=038.1 ； 8Hz=038.2 ； 10Hz=038.3 ； 12.5Hz=038.4 ； 16Hz=038.5 ； 20Hz=038.6 ；
25Hz=038.7； 31.5Hz=038.8 ； 40Hz=038.9；50Hz=038.1； 63Hz=063.2； 80Hz=038.3；
100Hz=038.4；125Hz=052.5；160Hz=038.6；200Hz=038.7；250Hz=044.8；315Hz=038.9；
400Hz=038.1；500Hz=038.2；630Hz=038.3；800Hz=038.4；1kHz=038.5；1.25kHz=038.6；
1.6kHz=038.7；2kHz=038.8；2.5kHz=038.9；3.15kHz=038.1；4kHz=038.2；5kHz=038.3；
6.3kHz=038.4；8kHz=038.5；10kHz=038.6；12.5kHz=038.7；16kHz=038.8；20kHz=038.9
02 01 41 31 2C 30 33 38 2E 31 2C 30 33 38 2E 32 2C 30 33 38 2E 33 2C 30
33 38 2E 34 2C 30 33 38 2E 31 2C 30 33 38 2E 32 2C 30 33 38 2E 33 2C 30
33 38 2E 34 2C 30 33 38 2E 35 2C 30 33 38 2E 36 2C 30 33 38 2E 37 2C 30
33 38 2E 38 2C 30 33 38 2E 39 2C 30 33 38 2E 31 2C 30 36 33 2E 32 2C 30
33 38 2E 33 2C 30 33 38 2E 34 2C 30 35 32 2E 35 2C 30 33 38 2E 36 2C 30
33 38 2E 37 2C 30 34 34 2E 38 2C 30 33 38 2E 39 2C 30 33 38 2E 31 2C 30
79

BSWA 308/309

BSWA Technology Co., Ltd

33 38 2E 32 2C 30 33 38 2E 33 2C 30 33 38 2E 34 2C 30 33 38 2E 35 2C 30
33 38 2E 36 2C 30 33 38 2E 37 2C 30 33 38 2E 38 2C 30 33 38 2E 39 2C 30
33 38 2E 31 2C 30 33 38 2E 32 2C 30 33 38 2E 33 2C 30 33 38 2E 34 2C 30
33 38 2E 35 2C 30 33 38 2E 36 2C 30 33 38 2E 37 2C 30 33 38 2E 38 2C 30
33 38 2E 39 03 7D 0D 0A

CUSp1_p2_p3_p4: Set Custom Measure
Instruction

P1

P2

p1: Group;

p2: Filter;

P3

Range: 1~14 0=A;

0=Fast;

0=SPL;

1=B;

1=Slow;

1=SD;

2=C;

2=Imp.

2=SEL;

3=Z
Explanation

P4

p3: Detector; p4: Mode;

3=E;
4=Max;

CUS

5=Min;
6=Peak;
7=LEQ;
8=LN1;
……
17=LN10

ASCII
Hex
Byte

C

U

S

43H 55H 53H
1

1

1

1

0

0

0

31H

30H

30H

30H

1

1

1~2

1~2

Return

ACK / NAK

Example: set custom measurement of group 1 to B-weighting, Fast, Peak.
02 01 43 43 55 53 31 20 31 20 30 20 36 03 20 0D 0A
Return: ACK
02 01 06 03 06 0D 0A
Default value of each group in custom measurement (parameter with * is actually useless):

80

Filter

Detector

Mode

Meaning

Custom 1

0

0

7

A, Fast*, LEQ

Custom 2

0

0

8

A*, Fast*, LN1

Custom 3

0

0

12

A*, Fast*, LN5

Custom 4

0

0

16

A*, Fast*, LN 9

Custom 5

0

0

4

A, Fast, Max

Custom 6

0

0

5

A, Fast, Min

BSWA 308/309

BSWA Technology Co., Ltd

Custom 7

0

0

1

A, Fast, SD

Custom 8

0

0

0

A, Fast, SPL

Custom 9

1

0

0

B, Fast, SPL

Custom 10

2

0

0

C, Fast, SPL

Custom 11

3

0

0

Z, Fast, SPL

Custom 12

0

0

2

A, Fast*, SEL

Custom 13

0

0

3

A, Fast*, E

Custom 14

2

0

6

C, Fast*, Peak

CUSp1_?: Query Custom Measure Setting
Instruction
Explanation

P1

P2

p1: Group

CUS

Query parameter: ?

1~14

ASCII

C

U

S

1

?

Hex

43H

55H

53H

31H

3FH

Byte

1

1

1

1~2

1

Return

Return custom measure setting

Example: query custom measure settings of group 12.
02 01 43 43 55 53 31 32 20 3F 03 1A 0D 0A
Return: the setting of group 12 is A-weighting, Fast, E.
02 01 41 31 32 2C 30 2C 30 2C 30 33 03 6D 0D 0A

TISp1_p2_p3_p4_p5: Set Timer
Instruction

Explanatio

TIS

n

P1

P2

P3

P4

p2: Start

p3: Start

p4: Start

P5:

Switch;

Day;

hour;

minute;

Repeat

0=OFF;

0=Ignore;

0~23=

0~59=

period;

1=ON;

1~31=

0~23h;

0~59m;

1~59=

Default: 0

1~31 day

Default:

Default: 0

1~59m;

form

12

60~83=

today;

1~24h;

Default: 0
ASCII
Hex
Byte
Return

T

I

S

54H 49H 53H
1

1

1

P5

P1:

Default: 1

0

0

12

0

1

30H

30H

31H, 32H

30H

31H

1

1

1~2

1~2

1~2

ACK / NAK

Example: set the Timer as switch: ON, start day: Ignore, start hour: 12:00, repeat period: 1m.
81

BSWA 308/309

BSWA Technology Co., Ltd

02 01 43 54 49 53 31 20 30 20 31 32 20 30 20 31 03 0E 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

TIS?: Query Timer Setting
Instruction

Parameters

TIS

Query parameter: ?

Explanation
ASCII

54H

49H

53H

?

Hex

1

1

1

3FH

Byte

54H

49H

53H

1

Return

Return Timer setting

Example: query Timer setting.
02 01 43 54 49 53 3F 03 32 0D 0A
Return: Timer setting is switch=OFF, start day=Ignore, Start Time=12:00, Repeat period=1m.
02 01 41 30 2C 30 30 2C 31 32 3A 30 30 2C 30 31 03 65 0D 0A

CONp1: Set Contrast
Instruction

Parameters
p1: Contrast;

Explanation

CON

Range:0~14;
Default: 7

ASCII

C

O

N

7

Hex

43H

4FH

4EH

37H

Byte

1

1

1

1

Return

ACK / NAK

Example: set the contrast as 9.
02 01 43 43 4F 4E 39 03 38 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

CON?: Query Contrast Setting
Explanation

Parameters

CON

Query parameter: ?

ASCII

C

O

N

?

Hex

43H

4FH

4EH

3FH

Byte

1

1

1

1

Return
82

Instruction

Return contrast setting

BSWA 308/309

BSWA Technology Co., Ltd

Example: query contrast setting
02 01 43 43 4F 4E 3F 03 3E 0D 0A
Returns: the current contrast is 7
02 01 41 30 37 03 46 0D 0A

BLTp1_p2: Set Backlight
Instruction

Explanation

Parameter 1

BLT

Parameter 2

p1: TimeOut;

p2: Delay;

0=ON, Auto shut down;

0=10s; 1=20s; 2=30s;

1=OFF, Never turn off;

3=40s; 4=50s; 5=60s;

Default: 0

Default: 0

ASCII

B

L

T

0

0

Hex

42H

4CH

54H

30H

30H

Byte

1

1

1

1

1

Return

ACK / NAK

Example: set backlight as timeout: ON, delay: 20s
02 01 43 42 4C 54 30 20 31 03 38 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

BLT?: Query Backlight Setting
Instruction

Parameters

BLT

Query parameter: ?

Explanation
ASCII

B

L

T

?

Hex

42H

4CH

54H

3FH

Byte

1

1

1

1

Return

Return backlight settings

Example: query the backlight settings
02 01 43 42 4C 54 3F 03 26 0D 0A
Return: the current backlight setting is timeout=OFF, delay=20s (delay is useless when
backlight timeout is OFF)
02 01 41 31 2C 31 03 6D 0D 0A

BAT?: Query Battery State
Explanation
ASCII

B

Instruction

Parameters

BAT

Query parameter: ?

A

T

?
83

BSWA 308/309

BSWA Technology Co., Ltd

Hex

42H

41H

54H

3FH

Byte

1

1

1

1

Returns the power state and supply voltage
Return

Power state: 0=Battery; 1=External power; 2=USB power
Supply voltage: xx.xx V

Example: query battery state
02 01 43 42 41 54 3F 03 2B 0D 0A
Returns: the current battery state is external power supply, supply voltage is 9.24V
02 01 41 31 2C 30 39 2E 32 34 03 7D 0D 0A

TRGp1: Set Trigger
Instruction

Parameters
p1: Trigger switch;

Explanation

0=OFF;

TRG

1=ON;
Default: 0

ASCII

T

R

G

0

Hex

54H

52H

47H

30H

Byte

1

1

1

1

Return

ACK / NAK

Example: set trigger as OFF
02 01 43 54 52 47 30 03 32 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

TRG?: Query Trigger Setting
Instruction

Parameters

TRG

Query parameter: ?

Explanation
ASCII

T

R

G

?

Hex

54H

52H

47H

3FH

Byte

1

1

1

1

Return
Example: query trigger setting
02 01 43 54 52 47 3F 03 3D 0D 0A
Returns: the current trigger setting is OFF
02 01 41 30 03 71 0D 0A

84

Return Trigger settings

BSWA 308/309

BSWA Technology Co., Ltd

DATp1_p2_p3_p4: Set Date
Instruction

P1

P2

p1: Date format;
Explanation

DAT

P3

p2: Year;

P4

p3: Month;

p4: Day;

0=Year/Month/Day; Range:

Range:

Range:

1=Month/Day/Year; 2000~2999

1~12

1~31

2=Day/Year/Month;
Default: 0
ASCII
Hex

D

A

T

0

44H 41H 54H

Byte

1

1

2011
32H, 30H

30H

1

31H, 31H

1

4

Return

1

1

31H

31H

1~2

1~2

ACK / NAK

Example: set the date format as year/month/day, date: 5th August 2011
02 01 43 44 41 54 30 20 32 30 31 31 20 38 20 35 03 0D 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

DAT?：Query Date Setting
Instruction

Parameters

DAT

Query parameter: ?

Explanation
ASCII

D

A

T

?

Hex

44H

41H

54H

3FH

Byte

1

1

1

1

Return

Return date setting

Example: query date
02 01 43 44 41 54 3F 03 2D 0D 0A
Return: the current date format=year/month/day, date=5th August 2011
02 01 41 30 2C 32 30 31 31 2F 30 38 2F 30 35 03 52 0D 0A

HORp1_p2_p3: Set Time
Instruction
Explanation

HOR

P1

P2

P3

p1: Hour;

p2: Minute;

p3: Second;

Range: 0~23h

Range: 0~59m

Range: 0~59s

ASCII

H

O

R

1

1

1

Hex

48H

4FH

52H

31H

31H

31H

85

BSWA 308/309
Byte

BSWA Technology Co., Ltd
1

1

1

1~2

Return

1~2

1~2

ACK / NAK

Example: set the time as 18:37:30
02 01 43 48 4F 52 31 38 20 33 37 20 33 30 03 18 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

HOR?: Query Time Setting
Instruction

Parameters

HOR

Query parameter: ?

Explanation
ASCII

H

O

R

?

Hex

48H

4FH

52H

3FH

Byte

1

1

1

1

Return

Return time settings

Example: query time setting
02 01 43 48 4F 52 3F 03 29 0D 0A
Returns: the current time is 18:37:48
02 01 41 31 38 3A 33 37 3A 34 38 03 40 0D 0A

PWOp1: Set Auto Power Off
Instruction

Parameters
p1: Auto power off time;

Explanation

0=1min; 1=5min; 2=10min;

PWO

3=30min; 4=OFF;
Default: 4

ASCII

P

W

O

4

Hex

50H

57H

4FH

34H

Byte

1

1

1

1

Return

ACK / NAK

Example: set auto power off as OFF
02 01 43 50 57 4F 34 03 3F 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

PWO?: Query Auto Power Off Setting
Explanation
86

Instruction

Parameters

PWO

Query parameter: ?

BSWA 308/309

BSWA Technology Co., Ltd

ASCII

P

W

O

?

Hex

50H

57H

4FH

3FH

Byte

1

1

1

1

Return

Return auto power off settings

Example: query auto power off settings
02 01 43 50 57 4F 3F 03 34 0D 0A
Returns: the current auto power off setting is OFF
02 01 41 34 03 75 0D 0A

OPMp1: Set Boot Mode
Instruction

Parameters
p1: Boot mode;
0=Normal;

Explanation

OPM

1=Power & Boot;
2=Boot & Auto Measure;
Default: 0

ASCII

O

P

M

0

Hex

4FH

50H

4DH

30H

Byte

1

1

1

1

Return

ACK / NAK

Example: set bott mode as normal
02 01 43 4F 50 4D 30 03 21 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

OPM?: Query Boot Mode Setting
Explanation

Instruction

Parameters

OPM

Query parameter: ?

ASCII

O

P

M

?

Hex

4FH

50H

4DH

3FH

Byte

1

1

1

1

Return

Return boot mode setting

Example: query boot mode
02 01 43 4F 50 4D 3F 03 2E 0D 0A
Return: the current boot mode is normal
02 01 41 30 03 71 0D 0A

87

BSWA 308/309

BSWA Technology Co., Ltd

UMDp1: Set USB Mode
Instruction

Parameters
p1: USB Mode;
0=Always Ask;

Explanation

UMD

1=U Disk Mode;
2=Modem Mode;
Default: 0

ASCII

U

M

D

0

Hex

55H

4DH

44H

30H

Byte

1

1

1

1

Return

ACK / NAK

Example: set to modem mode
02 01 43 55 4D 44 32 03 2D 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

UMD?: Query USB Mode Setting
Instruction

Parameters

UMD

Query parameter: ?

Explanation
ASCII

U

M

D

?

Hex

55H

4DH

44H

3FH

Byte

1

1

1

1

Return

Return USB mode setting

Example: query USB mode setting
02 01 43 55 4D 44 3F 03 20 0D 0A
Return: the current USB mode is modem mode
02 01 41 32 03 73 0D 0A

GPDp1_p2: Set GPS
Instruction

Explanation

P1

GPD

p1: GPS switch;

p2: Auto time sync;

0=OFF;

0=OFF;

1=ON;

1=ON;

Default: 0
ASCII
88

G

P

D

P2

Default: 0
0

0

BSWA 308/309

BSWA Technology Co., Ltd

Hex

47H

50H

44H

30H

30H

Byte

1

1

1

1

1

Return

ACK / NAK

Example: set GPS as switch: ON, auto time sync: ON
02 01 43 47 50 44 31 20 31 03 30 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

GPD?: Query GPS Setting
Instruction

Parameters

GPD

Query parameter: ?

Explanation
ASCII

G

P

D

?

Hex

47H

50H

44H

3FH

Byte

1

1

1

1

Return

Return GPS setting

Example: query GPS setting
02 01 43 47 50 44 3F 03 2D 0D 0A
Returns: the current GPS setting is switch=ON, auto time sync=ON
02 01 41 31 2C 31 03 6F 0D 0A

VER?: Query About Information
Instruction

Parameters

VER

Query parameter: ?

Explanation
ASCII

V

E

R

?

Hex

56H

45H

52H

3FH

Byte

1

1

1

1

Return

Return the about information

Example: query about information
02 01 43 56 45 52 3F 03 3D 0D 0A
Returns: type=309S, class=2, S/N=490001, version=3.00.141020, HWID=P0274.03.B11
02 01 41 33 30 39 53 2C 32 2C 34 39 30 30 30 31 2C 33 2E 30 30 2E 31 34
31 30 32 30 2C 50 30 32 37 34 2E 30 33 2E 42 31 31 03 33 0D 0A 03 70 0D
0A

LNGp1: Set Language
Instruction
Explanation

LNG

Parameters
p1: Language selection;
89

BSWA 308/309

BSWA Technology Co., Ltd
0=English; 1=Chinese;
2=Portuguese; 3=Spanish;
4=German; 5=French;
Default: 0

ASCII

L

N

G

0

Hex

4CH

4EH

47H

30H

Byte

1

1

1

1

Return

ACK / NAK

Example: set the language as Chinese
02 01 43 4C 4E 47 31 03 37 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

LNG?: Query Language Setting
Instruction

Parameters

LNG

Query parameter: ?

Explanation
ASCII

L

N

G

?

Hex

4CH

4EH

47H

3FH

Byte

1

1

1

1

Return

Return the language setting

Example: query language setting
02 01 43 4C 4E 47 3F 03 39 0D 0A
Returns: the current language is Chinese
02 01 41 31 03 70 0D 0A

OUTp1_p2_p3_p4: Set Output
Instruction

P1

P2

p1: Filter of p2:

Explanation

OUT

P3
p3: Mode

P4
p4: Output of

SLM;

Detector of of SLM;

Octave;

0=A;

SLM;

0=SPL;

0=LAeq;

1=B;

0=Fast;

1=LEQ;

1=LBeq;

2=C;

1=Slow;

2=Peak;

2=LCeq;

3=Z;

2=Imp.;

Default: 0

3=LZeq;

Default: 0

Default: 0

4~39=6.3Hz~20kHz;
Default: 0

ASCII
Hex
90

O

U

T

4FH 55H 54H

0

0

0

0

30H

30H

30H

30H

BSWA 308/309
Byte

BSWA Technology Co., Ltd
1

1

1

1

Return

1

1

1~2

ACK / NAK

Example: set the output to A-weighting, Fast, SPL for SLM. Set the output to LAeq for Octave
02 01 43 4F 55 54 30 20 30 20 30 20 30 03 2D 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

OUT?: Query Output Setting
Instruction

Parameters

OUT

Query parameter: ?

Explanation
ASCII

O

U

T

?

Hex

4FH

55H

54H

3FH

Byte

1

1

1

1

Return

Return output setting

Example: query output setting
02 01 43 4F 55 54 3F 03 32 0D 0A
Return: the output for SLM=A-weighting, Fast, SPL. For Octave=LAeq
02 01 41 30 2C 30 2C 30 2C 30 03 6D 0D 0A

RES: Apply Factory Settings
☆Note: After receipt of the ACK, user must wait at least 6 seconds to finish the operation.
Instruction
Explanation

Parameters

RES

None

ASCII

R

E

S

None

Hex

52H

45H

53H

None

Byte

1

1

1

None

Return

ACK / NAK

Example: apply the factory settings
02 01 43 52 45 53 03 07 0D 0A
Return: ACK. Wait at least 6 seconds after receipt of ACK
02 01 06 03 06 0D 0A

STAp1: Start / Stop Measurement
Instruction

Parameters
p1: Start / Stop measurement;

Explanation

STA

0=Stop;
1=Start
91

BSWA 308/309

BSWA Technology Co., Ltd

ASCII

S

T

A

1

Hex

53H

54H

41H

31H

Byte

1

1

1

1

Return

ACK / NAK

Example: start measurement
02 01 43 53 54 41 31 03 34 0D 0A
Return: ACK
02 01 06 03 06 0D 0A

STA?: Query Measurement State
Instruction

Parameters

STA

Query parameter: ?

Explanation
ASCII

S

T

A

?

Hex

53H

54H

41H

3FH

Byte

1

1

1

1

Return

Return measurement state

Example: query the measurement state
02 01 43 53 54 41 3F 03 3A 0D 0A
Returns: the measurement state is start (running)
02 01 41 31 03 70 0D 0A
☆Note: The following instructions are to query the sound level meter measurements data.
They contain the "return manner” parameter, it means:
Stop return: The sound level meter no longer to return measurements data every
second after received this instruction.
Single return: The sound level meter will return the measurements data on time after
received the instruction.
Continuous return: Automatically return the measurements data every second after
received the instruction.
Therefore, the "return manner" parameter in the instruction can be set to 2 and send to the
sound level meter, sound level meter will return the latest measurements data every second.

DMAp1_?: Query the Main Screen Data
Instruction

P1
p1:Return manner

Explanation

DMA

0=Stop return
1=Single return
2=Continuous return

92

P2
Query parameter: ?

BSWA 308/309

BSWA Technology Co., Ltd

ASCII

D

M

A

1

?

Hex

44H

4DH

41H

31H

3FH

1

1

1

1

1

Byte

Return the main screen data
Filter: 0=A, 1=B, 2=C, 3=Z
Return

Detector: 0=Fast, 1=Slow, 2=Imp.
Mode: 0=SPL, 1=PEAK, 2=LEQ, 3=MAX, 4=MIN
Measurement data: The value of the main screen

Example: query the data of the main screen, and return only once
02 01 43 44 4D 41 31 20 3F 03 25 0D 0A
Returns: the current main screen is: B-weighting, Slow, measurement data 066.1dB
02 01 41 31 2C 31 2C 32 2C 30 36 36 2E 31 03 70 0D 0A

TPRp1_?: Query 3-Profile Screen Data
Instruction

P1
p1: Return manner;

Explanation

P2
Query parameter: ?

0=Stop return;

TPR

1=Single return;
2=Continuous return

ASCII

T

P

R

1

?

Hex

54H

50H

52H

31H

3FH

Byte

1

1

1

1

1

Return 3-Profile screen data
Profile 1: Filter, Detector, Mode, Data

Return

Profile 2: Filter, Detector, Mode, Data
Profile 3: Filter, Detector, Mode, Data

Example: query 3-Profile screen data
02 01 43 54 50 52 31 20 3F 03 3B 0D 0A
Returns: the current 3-Profile screen data: profile 1: B-weighting, LEQ, 066.1dB; profile 2:
C-weighting, Fast, SPL, 067.1dB; profile 3: Z-weighting, Fast, SPL, 067.4dB
02 01 41 31 2C 31 2C 32 2C 30 36 36 2E 31 2C 32 2C 30 2C 30 2C 30 36 37
2E 31 2C 33 2C 30 2C 30 2C 30 36 37 2E 34 03 74 0D 0A

DLNp1_?: Query Statistical Analysis Data (LN)
Instruction
Explanation

DLN

P1
p1: Return manner;

P2
Query parameter: ?

0=Stop return;
93

BSWA 308/309

BSWA Technology Co., Ltd
1=Single return;
2=Continuous return

ASCII

D

L

N

1

?

Hex

44H

4CH

4EH

31H

3FH

Byte

1

1

1

1

1

Return statistical analysis (LN) data
Filter: 0=A, 1=B, 2=C, 3=Z
Detector: 0=Fast, 1=Slow, 2=Imp.
Return

Mode: 0=SPL
Group 1 LN percentages and LN statistics
……
Group 10 LN percentages and LN statistics

Example: query statistical analysis (LN) data
02 01 43 44 4C 4E 31 20 3F 03 2B 0D 0A
Returns: the current statistical analysis data is: A-weighting, Fast, SPL, LN10=065.4dB,
LN20=065.4dB, LN30=065.4dB, LN40=065.3dB, LN50=065.3dB, LN60=065.3dB,
LN70=035.2dB, LN80=065.2dB, LN 90=065.2dB, LN99=065.1dB
02 01 41 30 2C 30 2C 30 2C 31 30 2C 30 36 35 2E 34 2C 32 30 2C 30 36 35
2E 34 2C 33 30 2C 30 36 35 2E 34 2C 34 30 2C 30 36 35 2E 33 2C 35 30 2C
30 36 35 2E 33 2C 36 30 2C 30 36 35 2E 33 2C 37 30 2C 30 36 35 2E 32 2C
38 30 2C 30 36 35 2E 32 2C 39 30 2C 30 36 35 2E 32 2C 39 39 2C 30 36 35
2E 31 2C 03 58 0D 0A

DCU?: Query Custom Measure Data
Instruction

P1
p1: Return manner;

Explanation

P2
Query parameter: ?

0=Stop return;

DCU

1=Single return;
2=Continuous return

ASCII

D

C

U

1

?

Hex

44H

43H

55H

31H

3FH

Byte

1

1

1

1

1

Return custom measure data:
Return

Group 1Filter, Detector, Mode, Data
……
Group 14Filter, Detector, Mode, Data

Example: query custom measure data
02 01 43 44 43 55 31 20 3F 03 3F 0D 0A
94

BSWA 308/309

BSWA Technology Co., Ltd

Returns: the current custom measure data: Group 0: A-weighting, Fast*, L10, 065.4dB;
Group 1: A-weighting, Fast*, L20, 065.4dB; Group 2: A-weighting, Fast*, L60, 065.3dB;
Group 3: A-weighting, Fast*, L99, 065.1dB; Group 4: A-weighting, Fast, Min, 064.4dB; Group
5: A-weighting, Fast*, Peak, 081.9dB; Group 6: A-weighting, Fast, Sel, 083.8dB; Group7:
A-weighting, Fast, SPL, 065.3dB; Group 8: B-weighting, Fast, SPL, 066.4dB; Group 9:
A-weighting, Fast, SD, 005.6dB; Group10: B-weighting, Fast, SD, 007.2dB; Group 11:
A-weighting, Fast*, E, 2.696E-05dB; Group 12: A-weighting, Fast, Max, 65.5dB; Group 13:
B-weighting, Fast*, Leq, 066.2dB. ☆Note: Parameters with * are useless
02 01 41 30 2C 30 2C 30 38 2C 30 36 35 2E 34 2C 30 2C 30 2C 30 39 2C 30
36 35 2E 34 2C 30 2C 30 2C 31 33 2C 30 36 35 2E 33 2C 30 2C 30 2C 31 37
2C 30 36 35 2E 31 2C 30 2C 30 2C 30 35 2C 30 36 34 2E 34 2C 30 2C 30 2C
30 36 2C 30 38 31 2E 39 2C 30 2C 30 2C 30 32 2C 30 38 33 2E 38 2C 30 2C
30 2C 30 30 2C 30 36 35 2E 33 2C 31 2C 30 2C 30 30 2C 30 36 36 2E 34 2C
30 2C 30 2C 30 31 2C 30 30 35 2E 36 2C 31 2C 30 2C 30 31 2C 30 30 37 2E
32 2C 30 2C 30 2C 30 33 2C 32 2E 36 39 36 65 2D 30 35 2C 30 2C 30 2C 30
34 2C 30 36 35 2E 35 2C 31 2C 30 2C 30 37 2C 30 36 36 2E 32 03 2F 0D 0A

DSLp1_p2_?: Query All the Data of the Sound Level Meter
Instruction

Explanation

P1

DSL

P2

p1: Data

p2: Return

group;

manner;

0=SPL;

0=Stop return;

1=SD;

1=Single

2=SEL;

return;

3=E;

2=Continuous

4=Max;

return

P3

Query
parameter: ?

5=Min;
6=Peak;
7=Leq;
8=LN
ASCII

D

S

L

0

1

?

Hex

44H

53H

4CH

30H

31H

3FH

1

1

1

1

1

1

Byte

Return the corresponding group data:
Group 0: LAF, LAS, LAI, LBF, LBS, LBI, LCF, LCS, LCI, LZF, LZS, LZI
Return

Group 1: LAFsd, LASsd, LAIsd, LBFsd, LBSsd, LBIsd, LCFsd, LCSsd,
LCIsd, LZFsd, LZSsd, LZIsd
Group 2: LAsel, LBsel, LCsel, LZsel
95

BSWA 308/309

BSWA Technology Co., Ltd
Group 3: LAe, LBe, LCe, LZe
Group4: LAFmax, LASmax, LAImax, LBFmax, LBSmax, LBImax, LCFmax,
LCSmax, LCImax, LZFmax, LZSmax, LZImax
Group 5: LAFmin, LASmin, LAImin, LBFmin, LBSmin, LBImin, LCFmin,
LCSmin, LCImin, LZFmin, LZSmin, LZImin
Group 6: LApeak, LBpeak, LCpeak, LZpeak
Group 7: LAeq, LBeq, LCeq, LZeq
Group 8: Percentage values and statistics of ten LN

Example: query group 7 (LEQ)
02 01 43 44 53 4C 37 20 31 20 3F 03 21 0D 0A
Returns: the LEQ data: LAeq=065.0dB, LBeq=066.2dB; LCeq=067.0dB; LZeq=067.2dB
02 01 41 30 36 35 2E 30 2C 30 36 36 2E 32 2C 30 36 37 2E 30 2C 30 36 37
2E 32 03 6E 0D 0A

DOT?: Query 1/1 Octave Band Data
Instruction

P1

P2

p1: Return manner;
0=Stop return;
Explanation

DOT

1=Single return;

Query parameter: ?

2=Continuous
return;
ASCII

D

O

T

1

?

Hex

44H

4FH

54H

31H

3FH

1

1

1

1

1

Byte
Return

Return 1/1 octave band data: Filter, LAeq, LBeq, LCeq, LZeq, 8Hz, 16Hz,
31.5Hz, 63Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz, 16kHz

Example: query 1/1 octave data
02 01 43 44 4F 54 31 20 3F 03 32 0D 0A
Returns: the current 1/1 octave band filter is C-weighting, and data are: LAeq=064.7dB,
LBeq=066.0dB,

LCeq=066.8dB,

LZeq=067.1dB,

8Hz=030.7dB,

16Hz=041.6dB,

31.5Hz=048.4dB, 63Hz=053.9dB, 125Hz=056.8dB, 250Hz=059.5dB, 500Hz=060.8dB,
1kHz=060.3dB, 2kHz=057.8dB, 4kHz=053.6dB, 8kHz=047.0dB, 16kHz=035.4dB
02 01 41 31 2C 30 36 34 2E 37 2C 30 36 36 2E 30 2C 30 36 36 2E 38 2C 30
36 37 2E 31 2C 30 33 30 2E 37 2C 30 34 31 2E 36 2C 30 34 38 2E 34 2C 30
35 33 2E 39 2C 30 35 36 2E 38 2C 30 35 39 2E 35 2C 30 36 30 2E 38 2C 30
36 30 2E 33 2C 30 35 37 2E 38 2C 30 35 33 2E 36 2C 30 34 37 2E 30 2C 30
33 35 2E 34 03 7F 0D 0A

96

BSWA 308/309

BSWA Technology Co., Ltd

DTT?: Query 1/3 Octave Band Data
Instruction

P1

P2

p1: Return manner;
0=Stop return;
Explanation

DTT

1=Single return;

Query parameter: ?

2=Continuous
return;
ASCII

D

T

T

1

?

Hex

44H

54H

54H

31H

3FH

1

1

1

1

1

Byte

Return 1/3 octave band data: Filter, LAeq, LBeq, LCeq, LZeq, 6.3Hz, 8Hz,
10Hz, 12.5Hz, 16Hz, 20Hz, 25Hz, 31.5Hz, 40Hz, 50Hz, 63Hz, 80Hz,
Return

100Hz, 125Hz, 160Hz, 200Hz, 250Hz, 315Hz, 400Hz, 500Hz, 630Hz,
800Hz, 1kHz, 1.25kHz, 1.6kHz, 2kHz, 2.5kHz, 3.15kHz, 4kHz, 5kHz,
6.3kHz, 8kHz, 10kHz, 12.5kHz, 16kHz, 20kHz

Example: query 1/3 octave band data.
02 01 43 44 54 54 31 20 3F 03 00 0D 0A
Return: current Filter is C-weighting, LAeq=064.8dB, LBeq=066.0dB, LCeq=066.9dB,
LZeq=067.1dB,

6.3Hz=017.8dB,

8Hz=023.5dB,

16Hz=035.4dB,

20Hz=038.4dB,

25Hz=041.0dB,

0Hz=047.0dB,

63Hz=048.5dB,

80Hz=049.8dB,

10Hz=028.0dB,
31.5Hz=043.6dB,
100Hz=050.9dB,

12.5Hz=032.2dB,
40Hz=045.9dB,
125Hz=052.1dB,

160Hz=053.0dB, 200Hz=054.1dB, 250Hz=054.7dB, 315Hz=055.5dB, 400Hz=055.9dB,
500Hz=056.2dB, 630Hz=056.3dB, 800Hz=056.1dB, 1kHz=055.6dB, 1.25kHz=054.9dB,
1.6kHz=054.2dB, 2kHz=053.0dB, 2.5kHz=051.8dB, 3.15kHz=050.4dB, 4kHz=048.8dB,
5kHz=046.9dB, 6.3kHz=044.6dB, 8kHz=041.8dB, 10kHz=038.1dB, 12.5kHz=033.3dB,
16kHz=026.2dB, 20kHz=015.0dB
02 01 41 31 2C 30 36 34 2E 38 2C 30 36 36 2E 30 2C 30 36 36 2E 39 2C 30
36 37 2E 31 2C 30 31 37 2E 38 2C 30 32 33 2E 35 2C 30 32 38 2E 30 2C 30
33 32 2E 32 2C 30 33 35 2E 34 2C 30 33 38 2E 34 2C 30 34 31 2E 30 2C 30
34 33 2E 36 2C 30 34 35 2E 39 2C 30 34 37 2E 30 2C 30 34 38 2E 35 2C 30
34 39 2E 38 2C 30 35 30 2E 39 2C 30 35 32 2E 31 2C 30 35 33 2E 30 2C 30
35 34 2E 31 2C 30 35 34 2E 37 2C 30 35 35 2E 35 2C 30 35 35 2E 39 2C 30
35 36 2E 32 2C 30 35 36 2E 33 2C 30 35 36 2E 31 2C 30 35 35 2E 36 2C 30
35 34 2E 39 2C 30 35 34 2E 32 2C 30 35 33 2E 30 2C 30 35 31 2E 38 2C 30
35 30 2E 34 2C 30 34 38 2E 38 2C 30 34 36 2E 39 2C 30 34 34 2E 36 2C 30
34 31 2E 38 2C 30 33 38 2E 31 2C 30 33 33 2E 33 2C 30 32 36 2E 32 2C 30
31 35 2E 30 03 72 0D 0A

97

BSWA 308/309

BSWA Technology Co., Ltd

CSD: Save Custom Data into MicroSD
Instruction
Explanation

Parameters

CSD

None

ASCII

C

S

D

None

Hex

43H

53H

44H

None

1

1

1

None

Byte

Return state:
Return

0= Stored successfully, MicroSD OK;
1= Failure to store, MicroSD error;
2=No MicroSD.

Example: Save CSD
02 01 43 43 53 44 03 17 0D 0A
Return: save successfully, MicroSD OK
02 01 41 30 03 71 0D 0A

98

BSWA 308/309

BSWA Technology Co., Ltd

6. Operation Notes
6.1 Operation
 Please minimize the influence of vibration when using sound level meter, mechanical
vibration could affect indicated levels at the lower boundary of the measurement range at
frequencies within the range of the sound level meter (10Hz~20kHz).
 Sound level meter need at least 6 hours to reach equilibrium with the ambient
environment before switching on the power. After the equilibrium process and switching
on the power, no initial time need before sound level meter measure the level of sound.
 The measurement microphone is a sensitive component, please use it careful. Store the
microphone in the attached box which can protect it against damage from outside.
 Please follow the introduction and using step in the user manual. Do not drop, knock or
shake the product. Any operation over the limit could damage the product.
 Keep out the water and any other liquid due to no waterproof design on this product.
 Using qualified alkaline battery can extend your operation time and bring benefit to device.
Do not mix using of old and new batteries at the same time. Remove batteries when the
device is not in use. Long-term place the battery inside the product could cause battery
leakage and damage to the product.

6.2 Common Issue And Solutions
Issue

Possible Root Cause And Solution
 Low battery: replace battery;

Boot up failure.

 Power adapter failure: replace power adapter;
 Power button failure: please return to factory.

Inaccurate measurements.

Please try to calibrate again.

Measurement data don’t have

 Damaged microphone: return microphone to factory.

observable changes when

 Bad contact between microphone and main body:

sound source changed a lot.

please return the main body to factory.

Button failure.

Button was damaged: please return to factory.

Slow response when

Too much files in the MicroSD card: please delete the

operation.

trashy files.

99

BSWA 308/309

Can’t save the measurement
data.

BSWA Technology Co., Ltd
 Check logger settings.
 Format SD to FAT32.
 Replace new MicroSD card with maximum capacity 4G.

The Printer can’t print the

 Check the settings related to printer.

measurement data.

 Make sure the print-paper is installed correctly.

6.3 Calibration
Sound level meter has been calibrated before sales. Keep regular calibration can ensure the
accuracy of the measurement. BSWA provide the calibration service for acoustic products.

6.4 Firmware Update
BSWA 308/309 can update firmware via USB port. Following items need to be prepared:
 BSWA 308/309 sound level meter (HWID is P0274 and above) and keep off;
 MiniUSB cable (include in sales package);
 External power supply (include in sales package);
 Firmware for update (can be download from BSWA website);
 USB driver (Silicon Labs CP210x driver), can be find in CD-ROM or BSWA website;
 Firmware update tool: FlashTool Wizard, can be find in CD-ROM or BSWA website.
6.4.1 Install USB Driver
Unzip and install driver step by step.
Note that select X86 for 32-bit OS and
select X64 for 64-bit OS.
☆Note: Do not connect sound level
meter to computer when install driver.
Follow the prompt to install, accept the
license agreement and then click next
until the driver installation is complete.

100

BSWA 308/309

BSWA Technology Co., Ltd
After driver installation, connect sound
level meter to computer via USB cable,
a new device named Silicon Labs
CP210x USB to UART Bridge (COMx)
could be found in Device Manager.
☆Note: Power sound level meter by
external supply when connect to
computer.

6.4.2 Firmware Update Procedure
The firmware update software FlashTool Wizard is
very easy to use. Please just follow the prompt
step by step.
Run FlashTool Wizard and select language.

Step 1: prepare the list items for update firmware.

Step 2: Install the driver. Please skip if you already
install deriver before.

101

BSWA 308/309

BSWA Technology Co., Ltd
Step 3: Connect sound level meter and computer
according to the prompt. Note that sound level
meter needs external power supply. If driver is
working properly, it will automatically select Port of
CP210x. The default value of Baudrate is 115200,
which relate to the computer. Higher Baudrate can
fast the update procedure.
Step 4: first press the button located on the top
right corner

to select firmware, and then

press Update button to start. The whole procedure
need 3~4 minutes.
☆ Note: Reset to factory settings and run
calibration at least one time after firmware update,
otherwise sound level meter may note work
properly. If always display “Time Out!”, remove MicroSD card and try again.
There is no limitation for firmware to upgrade or downgrade, so user can update to any
version. Hence, we advise to keep the latest version of firmware. Please no hesitate to
contact us by phone call or e-mail to request support for any issue or bugs of firmware.
☆Note: Firmware update is a feature only available for new sound level meter with HWID:
P0274 and above. The old type of HWID: P0115 cannot update firmware by user. Following
list the difference of old and new type:
 In About page, P0115 displays type 308/309, while P0274 displays type 308S/309S.
 RS-232 port of P0115 using Lemo 3-pin socket, while P0274 using PS/2 6-pin socket.
 P0115 USB port is unavailable in function, while P0274 USB function is available.
 P0115 has two measurement ranges: High and Low, some early product also has Auto
range, while P0274 has only one range.

6.5 Warranty
BSWA can provide warranty service during the warranty period. The component could be
replaced according to the determination of BSWA to solve the issue caused by materials,
design or manufacture.
102

BSWA 308/309

BSWA Technology Co., Ltd

Please refer to the product warranty promise in sales contract. Do not try to open or repair the
device by customer. Any unauthorized behavior will result in loss warranty of this product

6.6 Customer Service Phone Number
Please do not hesitate to contact us for any issue:
Customer Service

+86-10-51285118-ext.222

(workday 9:00~17:00)

Phone Number:

+86-13671375687

(24h)

Sales Service

Please visit BSWA website www.bswa-tech.com to find the sales

Phone Number:

number of your region.

103

BSWA 308/309

BSWA Technology Co., Ltd

Annex 1 Glossary
 Frequency Weighting1: Difference, as a specified function of frequency, between the
level of the frequency weighted signal indicated on the display device and the
corresponding level of a constant amplitude sinusoidal input signal. Level difference is
expressed in decibels (dB). Frequency weighting usually have A, B, C and D-weighting,
which can simulate the response of human hearing. The A and C-weighting are more
commonly used and defined in IEC and GB/T standard. B-weighting is only defined in
ANSI standard. D-weighting related international standard is already withdrawn. Only
some old type instrument has D-weighting. No frequency weighting or to say flat response
always named as Z-weighting, Flat or Linear.
 Time Weighting1: Exponential function of time, of a specified time constant, that weights
the square of a sound pressure signal. The weighting of sound pressure is more higher if
it closer to the current time, and vice versa. Time weighting Fast and Slow are more
commonly used, while Impulse is not recommended to use and was reserved only for
historical reasons.
 SPL: Sound pressure level, SPL calculated in sound level meter is the greatest time
weighted sound level within 1 second.
 LEQ1: Time averaged sound level or equivalent continuous sound level. Ten times the
logarithm to the base 10 of the ratio of the time average of the square of a frequency
weighted sound pressure signal during a stated time interval to the square of the
reference value. The LEQ is actually integral value of sound level within stated duration.
The longer the integration period, the slower LEQ changes. LEQ is widely used in the
noise overall evaluation.
 Peak1: Peak sound level. Ten times the logarithm to the base 10 of the ratio of the square
of a frequency weighted peak sound pressure signal to the square of the reference value.
It’s usually used to evaluate the very short pulse of noise.
 E1: Sound exposure. Time integral of the square of a frequency weighted sound pressure
signal over a stated time interval or event of stated duration. It’s always used to evaluate
the impact of noise to human being.

104

BSWA 308/309

BSWA Technology Co., Ltd

 SEL1: Sound exposure level. Ten times the logarithm to the base 10 of the ratio of a sound
exposure to the reference value. It sometime called single event level.
 LN: Statistical analysis result. The noise level exceeded for N% of the measurement
period.
 Max1: Maximum time weighted sound level within stated duration.
 Min: Minimum time weighted sound level within stated duration.
 SD: Time weighted sound level of standard deviation within stated duration. SD is used to
describe the degree of dispersion changes of sound level.
Note 1: Refer to the definition of IEC 61672.1:2013 to earn more details.

105

BSWA 308/309

BSWA Technology Co., Ltd

Annex 2 Adjustments at the Calibration Check Frequency
Recommend to use CA111/CA114/CA115 sound calibrator for sensitivity calibration before
the measurement. The manual of sound calibrator provide the equivalent free field sound
level for 1/2” microphone as shown in the following table:
Calibration Sound Level for BSWA 308/309

Type of Sound
Frequency
Calibrator

106

Nominal 94dB

Nominal 114dB

CA111

1000Hz

93.8dB

113.8dB

CA114

1000Hz

93.8dB

N/A

CA115

1000Hz

N/A

113.8dB

BSWA 308/309

BSWA Technology Co., Ltd

Annex 3 Corrections for the Typical Effects of Reflections from the Case
of Sound Level Meter and Diffraction of Sound around the Microphone
Corrections for the Typical Effects of Reflections from the Case of the
Sound Level Meter and Diffraction of Sound around the Microphone
1.5

dB

1.0
0.5

0.0
-0.5
-1.0
Hz

*50.1187
79.4328
125.893
199.526
316.228
501.187
794.328
1.0593k
1.1885k
1.3335k
1.4962k
1.6788k
1.8836k
2.1135k
2.3714k
2.6607k
2.9854k
3.3497k
3.7584k
4.2170k
4.7315k
5.3088k
5.9566k
6.6834k
7.4989k
8.4140k
9.4406k
10.593k
11.885k
13.335k
14.962k
*16.788k
*18.836k

-1.5

Freq.

value

[Hz]

[dB]

Freq. value

Freq. value

Freq. value

Freq. value

Freq. value

[Hz]

[Hz]

[Hz]

[dB]

[Hz]

[dB]

[Hz]

[dB]

[dB]

[dB]

*50.119 -0.1

630.96 -0.1

1678.8 -0.1

3162.3

0.1

5956.6

0.9

11220

0.4

63.096

-0.1

794.33 -0.3

1778.3

0.1

3349.7

0.5

6309.6

0.6

11885

0.6

79.433

-0.2

1000.0

0.0

1883.6

0.0

3548.1

0.5

6683.4

0.6

12589

-0.1

100.00

-0.3

1059.3

0.0

1995.3

0.2

3758.4

0.0

7079.5

0.6

13335

-0.4

125.89

-0.3

1122.0 -0.1

2113.5

0.1

3981.1

0.2

7498.9 -0.8

14125

0.4

158.49

-0.2

1188.5

2238.7 -0.1

4217.0

0.4

7943.3 -0.1

14962

0.2

199.53

-0.1

1258.9 -0.2

2371.4

0.0

4466.8

0.1

8414.0

0.2

15849

-0.7

251.19

0.2

1333.5

0.0

2.511.9

0.2

4731.5

1.0

8912.5 -0.1

*16788

0.4

316.23

0.0

1412.5

0.0

2660.7

0.1

5011.9

0.7

9440.6

0.3

*17783

0.3

398.11

0.0

1496.2

0.1

2818.4 -1.0

5308.8

0.9

10000

0.2

*18836 -0.3

501.19

0.0

1584.9

0.1

2985.4

5623.4

0.3

10593

1.0

*19953 -0.4

0.0

0.2

Expanded Uncertainties: U=0.17 (k=2) @ <=4kHz, U=0.29 (k=2) @ >4kHz
Note: the frequency with * is not requirement of standard, refer to IEC 61672-1 for exact frequency.

107

BSWA 308/309

BSWA Technology Co., Ltd

Annex 4 Corrections of Windscreen in Free Field
Corrections of Windscreen in Free Filed
1.0

dB

0.5
0.0
-0.5
-1.0
-1.5
-2.0

*50.1187
*63.0957
*79.4328
*100.000
*125.893
*158.489
*199.526
*251.189
*316.228
*398.107
*501.187
*630.957
*794.328
1.00000k
1.25893k
1.58489k
1.99526k
2.51189k
3.16228k
3.98107k
5.01187k
6.30957k
7.94328k
10.0000k
12.5893k
15.8489k
*19.9526k

Hz

Freq. [Hz]

Value [dB]

Freq. [Hz]

Value [dB]

Freq. [Hz]

Value [dB]

*50.119

-0.04

*398.11

0.06

3162.3

0.12

*63.096

0.04

*501.19

0.04

3981.1

-0.24

*79.433

0.06

*630.96

0.06

5011.9

-0.30

*100.00

0.00

*794.33

0.09

6309.6

-0.33

*125.89

0.03

1000.0

0.14

7943.3

-0.66

*158.49

0.02

1258.9

0.24

10000

-0.71

*199.53

0.03

1584.9

0.30

12589

-1.04

*251.19

0.02

1995.3

0.37

15849

-1.37

*316.23

-0.01

2511.9

0.41

*19953

-1.92

Expanded Uncertainties: U=0.15 (k=2) @ <=4kHz, U=0.21 (k=2) @ >4kHz.
Note: the frequency with * is not requirement of standard, refer to IEC 61672-1 for exact frequency.

108

BSWA 308/309

BSWA Technology Co., Ltd

Annex 5 Corrections of Electrostatic Actuator
The following corrections are measured by BSWA EA002 electrostatic actuator and AS001
power supply.

Corrections of Electrostatic Actuator
10.0

dB

5.0

0.0

50.00
63.00
80.00
100.00
125.00
160.00
200.00
250.00
315.00
400.00
500.00
630.00
800.00
1000.00
1250.00
1600.00
2000.00
2500.00
3150.00
4000.00
5000.00
6300.00
8000.00
10000.00
12500.00
16000.00
20000.00

Hz

Freq. [Hz] Value [dB] Freq. [Hz] Value [dB] Freq. [Hz] Value [dB] Freq. [Hz] Value [dB]
200

0.000

630

0.043

2000

0.312

6300

2.184

224

0.002

710

0.053

2240

0.378

7100

2.651

250

0.004

800

0.065

2500

0.456

8000

3.204

280

0.006

900

0.080

2800

0.554

9000

3.840

315

0.009

1000

0.096

3150

0.678

10000

4.488

355

0.013

1120

0.116

3550

0.832

11200

5.264

400

0.017

1250

0.140

4000

1.020

12500

6.081

450

0.022

1400

0.170

4500

1.245

14000

6.960

500

0.027

1600

0.213

5000

1.488

16000

7.956

560

0.034

1800

0.260

5600

1.798

18000

8.664

20000

9.272

Expanded Uncertainties: U=0.19 (k=2) @ <=4kHz, U=0.34 (k=2) @ 4kHz~10kHz, U=0.39
(k=2) @ >=10kHz.

109

BSWA 308/309

BSWA Technology Co., Ltd

Annex 6 Typical Frequency Response and Corresponding
Upper Limit
Each microphone was test carefully before go out of factory, the calibration chart in the
attached box describe the real response of electrostatic actuator and free filed.
The typical response of frequency weighting of sound level meter as shown in the following
figure. The typical response plus free field response of microphone can be considered as the
totally response of sound level meter in free field. The certificate of calibration also include
the real test result of response of A, C and Z-weighting.

Typical Response of Frequency Weighting of Sound Level Meter
10.0

dB

0.0
-10.0
-20.0
-30.0

A-weighting

-40.0

B-weighting

-50.0

C-weighting

-60.0

Z-weighting

-70.0
-80.0

Hz
10

100

1000

10000

Base on the typical response of above figure, the impact to upper limit of measurement range
for A, B and C-weighting as shown in the following table:
Freq. [Hz]
A-weighting

8*

16*

31.5

63

125

250

500

1k

2k

4k

8k

16k*

-74.8 -56.3 -39.5 -26.2 -16.2

-8.7

-3.3

0.0

+1.3

+1.2

-0.5

-9.7

-43.2 -28.2 -17.1

-9.4

-4.3

-1.4

-0.3

0.0

0.0

-0.5

-2.3

-11.6

-17.4

-0.8

-0.2

0.0

0.0

0.0

-0.1

-0.6

-2.4

-11.7

[dB]
B-weighting
[dB]
C-weighting

-8.4

-3.0

[dB]
Note *: only available for BSWA 308.

110

BSWA 308/309

BSWA Technology Co., Ltd

Annex 7 Specification of 1/1 Octave Band Filter
1/1 octave filter was designed by the Butterworth filter and base 10 system. The specification
of each filter as the shown in the following figure:
8Hz ~ 250Hz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

0.1

1
8Hz

16Hz

10
31.5Hz

100
63Hz

125Hz

Hz
1000
250Hz

500Hz ~ 16kHz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

10

100
500Hz

1kHz

1000
2kHz

10000
4kHz

8kHz

Hz
100000
16kHz

111

BSWA 308/309

BSWA Technology Co., Ltd

Annex 8 Specification of 1/3 Octave Band Filter
1/3 octave filter was designed by the Butterworth filter and base 10 system. The specification
of each filter as the shown in the following figure:
6.3Hz ~ 20Hz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

1

Hz
100

10
6.3Hz

8Hz

10Hz

12.5Hz

16Hz

20Hz

25Hz ~ 80Hz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

Hz
1

10
25Hz

112

31.5Hz

100
40Hz

50Hz

63Hz

80Hz

BSWA 308/309

BSWA Technology Co., Ltd

100Hz ~ 315Hz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

10

Hz
1000

100
100Hz

125Hz

160Hz

200Hz

250Hz

315Hz

400Hz ~ 1.25kHz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

Hz
10

100
400Hz

500Hz

1000
630Hz

800Hz

1kHz

1.25kHz

113

BSWA 308/309

BSWA Technology Co., Ltd

1.6kHz ~ 5kHz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

Hz
100

1000
1.6kHz

2kHz

10000

2.5kHz

3.15kHz

4kHz

5kHz

6.3kHz ~ 20kHz Octave Filter Response

10.0
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0

dB

1000
6.3kHz

114

Hz
100000

10000
8kHz

10kHz

12.5kHz

16kHz

20kHz

BSWA 308/309

BSWA Technology Co., Ltd

Annex 9 Mid-band Frequencies for 1/1 Octave Band and 1/3
Octave Band Filters
Base 10 Exact fm
Nominal Midband
1/1 Octave Band
1/3 Octave Band
[Hz]
Frequency [Hz]
6.3096
6.3
X
7.9433
8
X
X
10.000
10
X
12.589
12.5
X
15.849
16
X
X
19.953
20
X
25.119
25
X
31.623
31.5
X
X
39.811
40
X
50.119
50
X
63.096
63
X
X
79.433
80
X
100.00
100
X
125.89
125
X
X
158.49
160
X
199.53
200
X
251.19
250
X
X
316.23
315
X
398.11
400
X
501.19
500
X
X
630.96
630
X
794.33
800
X
1000.0
1000
X
X
1258.9
1250
X
1584.9
1600
X
1995.3
2000
X
X
2511.9
2500
X
3162.3
3150
X
3981.1
4000
X
X
5011.9
5000
X
6309.6
6300
X
7943.3
8000
X
X
10000
10000
X
12589
12500
X
15849
16000
X
X
19953
20000
X
Note: Exact mid-band frequencies were calculated to five significant digits.

115

BSWA Technology Co., Ltd
Room 1003, North Ring Center, No.18 Yumin Road,
Xicheng District, Beijing 100029, China
Tel: 86-10-5128 5118
Fax: 86-10-8225 1626
E-mail: info@bswa-tech.com
URL: www.bswa-tech.com
2016 BSWA



---

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.5
Linearized                      : No
Page Count                      : 118
Language                        : zh-CN
Tagged PDF                      : Yes
Author                          : GreatMan
Creator                         : Microsoft® Word 2010
Create Date                     : 2016:06:07 17:00:08+08:00
Modify Date                     : 2016:06:07 17:00:08+08:00
Producer                        : Microsoft® Word 2010

EXIF Metadata provided by EXIF.tools