Product Data Sheet BRK_4375 BRK 4375

User Manual: BRK_4375

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Product Data

DeltaShear

Piezoelectric DeltaShear® Accelerometers
Uni-Gain®, DeltaTron® and Special Types
“V” Types: 4321V, 4370V, 4371V, 4375V, 4381V, 4382V, 4383V, 4384V, 4391V and 4393V
Uni-Gain® Types: 4321, 4370, 4371, 4375, 4378, 4379, 4381, 4382, 4383, 4384, 4391, 4393,
Uni-Gain® DeltaTron® Types: 4394, 4395, 4396, 4397, 4398 and 4399
Special Types: 4326, 4374, 8305, 8309, 8318 and 8319
USES:

❍

DeltaTron® and Line-drive types with integral
preamplifer

❍

Shock and vibration measurement and analysis

❍

Vibration monitoring

❍

Acceleration ranges cover 20 µ ms–2 to 1000 kms–2

❍

Modal and structural analysis

❍

❍

Vibration test control

Frequency ranges cover from a fraction of a Hz to
60 kHz (+10% limit)

❍

Production and quality control

❍

❍

Low sensitivity to extraneous environmental
influences including temperature fluctuations

❍

Low sensitivity to base bending effects

❍

Individual calibration supplied

❍

Artificially aged for long term stability

FEATURES:
❍

❍

Competitively priced DeltaShear® “V” Types,
especially suitable for permanent set-ups
Uni-Gain

®

types for easy interchangeability

4384
4384V

Temperature ranges cover – 74°C to +250°C (–101
to +482°F)

4371
4371V

4383
4383V

4382
4382V

4370
4379V

4379

4381
4381V

4378

8309

8305

4394

4395

4374

4375
4375V

4396

4391
4391V

8318

4393
4393V

4397

Brüel & Kjær

4398

B

4399

K

8319

4326

4321
4321V

celerometer Type 4374, Standard
Reference Accelerometer Type 8305
and Shock Accelerometer Type 8309,
all the piezoelectric accelerometers in
this data sheet use the DeltaShear®
design (see Fig. 1). Type 4374 uses
the planar shear design, Type 8305
uses the inverted centre mounted
compression design and Type 8309
uses the centre mounted compression
design as shown in Fig. 3.

The Brüel & Kjær transducer range
incorporates accelerometers suitable for
nearly all application requirements. In
addition to the comprehensive range of
piezoelectric accelerometers described
in this Data Sheet, Brüel & Kjær supply
accelerometers for heavy-duty industrial use and transducers specifically designed for special purpose applications.
A summary of other Brüel & Kjær
accelerometers is given on the back
cover and further details of these
transducers are given in their respective Product Data sheets.

The active element of Brüel & Kjær
accelerometers consists of piezoelectric discs or slices loaded by seismic
masses and held in position by a
clamping arrangement. When the accelerometer is subjected to vibration,
the combined seismic mass exerts a
variable force on the piezoelectric element. Due to the piezoelectric effect,
this force produces a corresponding
electrical charge.
For frequencies from DC up to approximately one third of the resonance frequency of the accelerometer
assembly, the acceleration of the seismic mass is equal to the acceleration
of the whole transducer. Consequently, the charge produced by the piezoelectric element is proportional to the
acceleration to which the transducer
is subjected.
The electrical signal output from
Brüel & Kjær Accelerometers is selfgenerated, though the types with
built-in preamplifiers require an external power supply for this signal to
be measured.
All the piezoelectric accelerometer
types described in this Product Data
sheet are supplied with an individual
calibration chart and in most cases
an individually measured frequency
response curve. Data from these
charts are summarized in the Specifications.

Fig.1 The unique Brüel & Kjær DeltaShear design. M=Seismic Mass,
P=Piezoelectric Element, B=base and
R=Clamping Ring

tivity, are typical. In contrast the sensitivity and other parameters for the
Uni-Gain® accelerometers are guaranteed within tight tolerances for
easy interchangeability without recalibration (see specifications on page
16 and 17). Except for the sensitivity,
everything in this Product Data applies to both types.

The piezoelectric elements of most
of the accelerometers are PZ 23 lead
zirconate titanate elements. The
Shock Accelerometer Type 8309 has
a specially formulated ferroelectric
ceramic PZ 45. The Miniature Accelerometer Type 4374 and the High
Sensitivity Accelerometers Types
4378 and 4379 have a lead zirconate
titanate element PZ 27.
The housing material of all the accelerometers is the same as the base
material (given in the Specifications)
except Type 4374, which has an nickel-chromium alloy housing.

Uni-Gain® Sensitivity
This designation indicates that the
measured accelerometer sensitivity
has been adjusted during manufacture to within 2% of a convenient value, for example (in 10 dB steps) 1,
3.16 or 10 pC/ms–2.

Design and Construction
All the accelerometers except Types
4321, 4321V and 4326 measure
uniaxial acceleration. These types
measure accelerations in three mutually perpendicular directions.
With the exception of Triaxial Accelerometer Type 4326, Miniature Ac-

Fig.2 All DeltaShear® “V” types are supplied in a robust plastic box

“V” and Uni-Gain® Types
Some of the piezoelectric accelerometers described in this Product Data
sheet are available both as “V” types
as well as Uni-Gain® types. The DeltaShear® without Uni-Gain® types
are recognized by the “V” suffix in
the type name. The only difference
between these two types is that all
the specifications on the calibration
chart for “V” types, except the sensi2

Fig.3 Comparison and PlanarShear designs. M =Seismic Mass, P=Piezoelectric Element, B=Base, R=Clamping Ring and S=Spring

Characteristics
Charge and Voltage Sensitivity
A piezoelectric accelerometer may be
treated as a charge or voltage source.
Its sensitivity is defined as the ratio
of its output to the acceleration it is
subjected to, and may be expressed
in terms of charge per unit acceleration (e.g. pC/ms–2) or in terms of voltage per unit acceleration (e.g. mV/
ms–2).
The sensitivities given in the individual Calibration Charts have been
measured at 160 Hz with an acceleration of 100 ms–2. For a 99.9% confidence level the accuracy of the
factory calibration is ± 2% and includes the influence of the connecting
cable supplied with each accelerometer. With the exception of Triaxial Accelerometers Types 4321, 4321V and
Lower Frequency
Limit

Type no.

4326, the direction of main axis sensitivity for these accelerometers is
perpendicular to the base plane of the
accelerometers. Types 4321, 4321V
and 4326 have three mutually perpendicular axes of sensitivity.
DeltaShear® Accelerometers
The Delta design involves three piezoelectric elements and three masses
arranged in a triangular configuration around a triangular centre post,
as illustrated in Fig. 1. The Delta
Shear® design gives a high sensitivity-to-mass ratio compared to other
designs, a relatively high resonance
frequency and high isolation from
base strains and temperature transients. The excellent overall characteristics of this design make it ideal
for both general purpose accelerometers and more specialized types.

Sensitivity
pC/ms–2

4321

1 ± 2%

4326

0.3

4370, 4381

10 ± 2%

4371, 4384

1 ± 2%

4374

DeltaTron® Accelerometers
DeltaTron® accelerometers operate
on a constant-current power supply
and give output signals in the form
of voltage modulation on the power
supply line. Types 4394, 4395 and
4396 have insulated base. All DeltaTron® accelerometers are individually calibrated Uni-Gain® types.
Line-drive Accelerometers
High Sensitivity Line Drive Accelerometer Type 8318 and Underwater
Accelerometer Type 8319 have builtin preamplifiers and operate according to the principle of current modulation (constant voltage supply). The
Line-drive principle allows cable
lengths of up to 1 km.

Upper Frequency
Limit

Y

X

Z

≅ 0.11

4375, 4393 0.316 ± 2%
4378, 4379

31.6 ± 2%

4382, 4383

3.16 ± 2%

4391

0.1

0.2

0.5

1.0 Hz

1 ± 2%

4394, 4397

1 ± 2%†

4395, 4398

1 ± 2%†

4396, 4399

10 ± 2%†

8309

≅ 0.004

8318

316 ± 2%
1 kHz

1.5

2

2.5 3

4

5

6

7 8 9 10 12

15

20

25 30

40

50 60

80 100
851205/2e

Fig.4 Upper and lower frequency limits (10%) and sensitivities of accelerometers. ▲ denotes a line-drive type where the sensitivity is
given in µA/ms– 2. Frequency limits also apply to “V” types

Fig.5 Example of the calibration chart supplied with the Brüel & Kjær accelerometers, together with a frequency response curve
3

Lower Dynamic Measurement Limit
for signal to noise ratio > 6 dB
A
L
A
L
A

Weight
grams

4321

55

4326

10

4370 4381

L
A
L
A
L
A
L

A
L
A
L
A
L

A
A

A
L

A

S
43

C

4371, 4384

11

4374

0.65†

C

4375 4393

2.4†

C

4378, 4379

175

4382, 4383

17

4391

16

8309
8318

5
2

C
C
S
S
S
S
C
S
C
S
C
S
C
S
C
S

2.4

C
S

4396* 4399* 18.2 17.1

L

1

S

4395* 4398* 12.9 11.8

L
A

0.5

Upper Dynamic Measurement Limit
C

54

4394* 4397* 2.9

L

L
0.05
0.2
0.02
0.1

Type no.

20
10

100
50

200

500
1000 mms–2

C

3†
C
470
S
0.005
0.02
0.1
0.01 kms–2 0.05
0.2

0.5

2.0
1.0

10
5.0

50
20

S

200
100

1000
500

851206/2e

Fig.6 Upper and lower dynamic measurement limits and weights of the accelerometers. Maximum limits (C = continuous sinusoidal
vibration and S = shock) are peak values. Minimum limits (A = 1/3 -octave bandwidth up to individual accelerometer +10% upper
frequency limit and L = Lin 2 Hz to 22 kHz) are RMS values. The dynamic limits are typical measurable vibration levels using the
accelerometers plus Brüel & Kjær Charge Amplifier Type 2635. † denotes cable weight excluded. * Upper limit for shock is measured
in the axial direction. Limits also apply to “V” types

Transverse Sensitivity
Accelerometers are slightly sensitive
to acceleration normal to their main
sensitivity axis. This transverse sensitivity is measured during the factory calibration process using a 30 Hz
and 100 ms–2 excitation, and is given
as a percentage of the corresponding
main axis sensitivity.
Most
Uni-Gain®-Delta Shear®
types have an indication of the angle
of minimum transverse sensitivity.
Frequency response
The upper frequency limits given in
the specifications are calculated as
30% and 22% of the mounted resonance frequency to give errors of less
than 10% and 5% respectively. These
calculations assume that the accelerometer is properly fixed to the test
specimen, as poor mounting can have
a marked effect on the mounted resonance frequency.
The low-frequency response of an
accelerometer depends primarily on
the type of preamplifier used in the
measurement set-up. A detailed discussion of the effects of the measuring system on the low-frequency
response of an accelerometer is given
in the Brüel & Kjær “Piezoelectric Accelerometers and Vibration Preamplifiers Handbook”.
Line-drive Accelerometer Type
8318 and Underwater Accelerometer
Type 8319 have a built-in preampli4

fier with a specified lower limiting
frequency (LLF 10% limit) of 0.1 Hz
and 0.3 Hz respectively.

cube using a Calibration Exciter Type
4290.

Most of the standard piezoelectric
accelerometers types are supplied
with an individual frequency response curve attached to their calibration chart. Types 4374, 4375, 4393
and all Delta Shear® (without UniGain®) types are not supplied with
individual curves.
DeltaTron® types are supplied with
individual frequency curves from 10
to 10000 Hz as well as typical curves
above and below this range.

Phase Response and Damping
The low damping of Brüel & Kjær Accelerometers leads to the single, well
defined resonance peak plotted on
the individual frequency response
curves. Brüel & Kjær accelerometers
can be used at frequencies up to 30%
of their mounted resonance frequency
without noticeable phase distortion
being introduced. The phase response
up to this frequency is 0° ± 1°.

Transverse Resonance Frequency
Typical values for the transverse resonance frequency are obtained by vibrating the accelerometers mounted
on the side of a steel or beryllium

Dynamic Range
The dynamic range defines the range
over which its electrical output is directly proportional to the acceleration
applied to its base.

Ca
Ra

Qa

Ca

Ra

Charge Equivalent

Cc

Cc

Va =

Qa
Ca + Cc

Voltage Equivalent
760321e

Fig.7 Equivalent circuit diagrams for accelerometers

Upper Limit
In general, the smaller the accelerometer the higher the vibration level
at which it can be used. The upper
limit depends on the type of vibration, and is determined by the prestressing of the piezoelectric element
as well as by the mechanical strength
of the element.
For accelerometers with built-in
preamplifiers, the maximum shock
and continuous vibration limits given
in the Specifications are measuring
limits. For transportation and handling the maximum shock (± Peak
Transport) and maximum continuous
sinusoidal acceleration (± Peak Transport) limits for the Type 8318 are
1 kms–2 and 0.3 kms –2 respectively.
The maximum shock and continuous vibration limits are specified for
vibration in any direction and for frequencies of up to one third of the
mounted resonance frequency.
When measuring short duration
transient signals, care must be taken
to avoid ringing effects due to the
high-frequency resonance of the accelerometer. A general rule of thumb
for a half sine shock pulse to obtain
amplitude errors of less than 5%, is
to ensure that the duration of the
pulse exceeds 10/fR , where fR is the
mounted resonance frequency of the
accelerometer.
Lower Limit
Theoretically, the output of a piezoelectric accelerometer is linear down
to the acceleration of the seismic
mass due to the thermal noise, but a
practical lower limit is imposed by
the noise level of the measurement
system and by the environment in
which measurements are made. Details concerning the selection of a
suitable preamplifier, together with a
discussion of environmental influences, can be found in the Brüel & Kjær
“Piezoelectric Accelerometers and Vibration Preamplifiers” handbook.

Fig.8 Aluminium screen used as a heat
shield allowing the accelerometer to be
operated at high temperatures (for example, Type 4370 up to 350 °C

Electrical Impedance
Fig. 7 shows the equivalent circuit diagram for accelerometers without
built-in preamplifiers. Since the leakage resistance is very high, the accelerometers can be regarded as purely
capacitive and the capacitances given
in the Specifications are measured at
160 Hz.
Line-drive accelerometers can be
regarded as current sources, the ideal
output impedance for a current
source being infinite. The output impedance of these accelerometers is
specified as a minimum resistance in
Ohms (Ω).
DeltaTron® accelerometers can be
regarded as voltage sources, the ideal
output impedance for an output
source being zero. The output impedance of these accelerometers is specified as a maximum resistance in
Ohms (Ω).

Environmental
Characteristics
Temperature
All Brüel & Kjær accelerometers are
rated for a maximum operating temperature limit. At lower temperatures, the accelerometer piezoelectric
element will exhibit temperature dependent variations in charge and
voltage sensitivity, as well as impedance. Details of these variations are
given on the individual calibration
chart supplied with each accelerometer (see Fig. 5).
The lower temperature limit for
most accelerometers is specified as
–74°C (–101°F), though this does not
preclude the use of the accelerometers at lower temperatures.
To make measurements on surfaces
with very high temperatures some
form of cooling is needed. Fig. 8 illustrates a method using a thin conductive plate and mica washer. For a
250°C (482°F) accelerometer this

Fig.9 Sealing the accelerometer output
connector for operation in humid environments

methods allows measurements to be
made on surfaces with temperatures
of up to 350°C (662°F). With extra
cooling, achieved by directing a
stream of cooling air at the plate, surface temperatures of up to 450°C
(842°F) may be tolerated.
When the insulating stud YP 0150
is used to mount an accelerometer at
operating temperatures greater than
80°C, creeping may occur causing a
reduction in the mounted resonant
frequency, and a lowering of the maximum shock capability.
Temperature Transients
Piezoelectric accelerometers exhibit a
small sensitivity to temperature fluctuations. This effect is significant
when low frequency, low level accelerations are being measured.
The temperature transient sensitivity is determined by attaching the
accelerometer to an aluminium block,
with a weight approximately ten
times that of the accelerometer, and
immersing these in a liquid bath
where the temperature difference
from room temperature is approximately 30°C. The maximum resulting
output from the accelerometer is recorded, and the sensitivity given in
ms–2/°C for a specified LLF. This output will be approximately inversely
proportional to the LLF.
Humidity
Brüel& Kjær accelerometers are sealed
with either a welded, or epoxy sealed
housing giving a high resistance to the
majority of corrosive agents found in
industry. Use of moisture impervious
Teflon cables and sealing, as shown in
Fig. 9, will permit use in environments
where heavy condensation is likely.
Suitable sealants are Dow Corning’s
RTV 738 or similar compounds.
Acoustic Pressure
The
acoustic
sensitivity
of
Brüel & Kjær accelerometers is low
and for most vibration measurement
applications can be neglected. Normally the acoustically induced vibration signal from the structure being
measured is much greater than the
signal due to the acoustic sensitivity.
The acoustic sensitivity is specified
as the equivalent acceleration given
by a 154 dB sound pressure level and
measured in the frequency range 2 to
100 Hz.
Nuclear Radiation
Except Types with built-in preamplifier all Brüel & Kjær accelerometers
5

Fig.11 Recommended tolerances for the mounting surfaces. Dimensions and symbols in
accordance with ISO 1101

Fig.10 Recommended mounting
nique using a steel stud

tech-

may be used under gamma radiation
(100 Gy/h, 6 MeV) up to accumulated
doses of 20 kGy (1 Gy = 100 Rad).
Tests indicate that these accelerometers show less than 10% sensitivity
change after such exposure. Normal
types of accelerometer cable may be
used, but special cables are recommended for accumulated doses exceeding 1 k Gy. For greater exposure
levels or for use under heavy neutron
radiation, Industrial Accelerometer
Type 8324 is recommended, and special cables are available (see separate
Product Data sheet).
Base Strains
These may be introduced into the accelerometer by distortion of the structure being measured. To minimise
base strain outputs the DeltaShear®
design is used.
The base strain sensitivity of
Brüel & Kjær accelerometers is measured by mounting the accelerometer
on a cantilever beam, and producing
a strain of 250 µε at the point of attachment. The sensitivity is calculated from the resulting output, and is
given in ms–2/µε.

Mounting
Brüel & Kjær accelerometers can be
mounted with their main sensitivity
axis aligned in any direction.
Recommended Mounting Technique
Fig. 10 shows the recommended
mounting method for most of the accelerometer types. The accelerome6

Fig.12 Alternative mounting techniques

ters are screwed using a threaded
steel stud onto a clean metal surface
meeting the requirements specified
in Fig. 11. Under normal circumstances the absolute minimum depth
of 4 mm will not be sufficient to accommodate the mounting stud, but is
the minimum depth required to hold
a stud securely. The optimum torque
for tightening 10–32 UNF steel studs
is 1.8 Nm (15 lb in), for M3 steel studs
it is 0.6 Nm (5 lb in) and for M8 steel
studs it is 4.6 Nm (38 lb in).
This mounting method is used in
obtaining the specifications of all the
accelerometers with the following exceptions:
Type 4374 which, due to its small
size, cannot be mounted using a stud.
The recommended mounting technique, used to obtain the specifications, utilises a quick setting methyl
cyanoacrylate cement (Brüel & Kjær
no. QS 0007). The tolerances on the

clean metal mounting surface shown
in Fig. 11 are required.
Type 8309 has an M5 metric screw
stud as an integral part of its base.
The tolerances shown in Fig. 11 apply, and the optimum torque is
1.8 Nm (15 lb in).
When using the recommended
technique, it should also be noted
that if the mounting surface is not
perfectly smooth, the application of a
thin layer of grease to the base of the
accelerometer before screwing it
down on the mounting surface will
improve the mounting stiffness.
Alternative Mounting Techniques
When mounting techniques other
than the recommended technique are
used, the accelerometer mounted resonance frequency will probably be
lowered.
Fig. 12 shows some alternative
mounting techniques. The section en-

titled Standard Accessories lists the
mounting accessories that are supplied with the individual accelerometer
types.
These
mounting
techniques are described in more detail in the Brüel & Kjær “Piezoelectric
Accelerometers and Vibration Preamplifiers” handbook, where the effects
of the different methods on the frequency response curve of an accelerometer are illustrated.
Fig.13 Clamping the accelerometer cable to minimize cable noise

Connecting Cables
A number of cables are available for
connection of Brüel & Kjær accelerometers. Refer to page 19 and 20 for
an overview of the various cables and
connector types.
Types 4391, 4391V and 4391E require TNC connectors. Type 8318,
which also requires a TNC connector,
is supplied with a spiral, TNC to TNC
connector, cable AO 0268. Type 8319
is supplied with a 10 m integral cable
with a TNC connector. Miniature Accelerometers Types 4374, 4375 and
4375V have integral cables, with a
minimum length of 0.32 m, and miniature coaxial plugs. Furthermore,
extension connectors and cable
AO 0038 are supplied.
Types 4393 and 4393V require subminiature connectors. Type 4393 is
supplied with a subminiature to miniature plug coaxial cable AO 0283.
All cables include a special noise
reduction treatment and are individually tested with regard to mechanical and electrical performance. The
max. temperature rating is 260°C
(500°F) except for cable AO 0268
which is rated at 85°C (185°F).
DeltaTron® accelerometers are
supplied with a double-screened cable to reduce the electromagnetic interference to the absolute minimum.
The section entitled Standard Accessories lists the cables and connectors
supplied
with
each
accelerometer.
Additional
cable
lengths and connectors can be ordered (see Additional Accessories
Available and the Cables With and
Without Connectors table). Details of
the accelerometer connections and
recommended plug clearances can be
found in the section entitled Accelerometer Dimensions.
It is good practice to clamp down
loose cables, as shown in Fig. 13, and
this will also help to reduce any possibility of dynamically induced noise
being generated by the cables.

Fig.14 Brüel & Kjær vibration preamplifiers with charge input

932238/1e

Fig.15 Calibration instrumentation

Preamplifiers and Power
Supplies

Supply WB 1372 or 8 Channel DeltaTron® Supply Type 5963. DeltaTron®
Amplifier Type 2646 is a miniature
charge to DeltaTron® amplifier.

With the exception of DeltaTron® accelerometers that have built-in
preamplifiers, the outputs from
Brüel & Kjær charge accelerometers
need to be fed through a preamplifier.
Charge amplifiers are recommended,
and Brüel & Kjær produce a wide selection of high performance preamplifiers for this purpose (see Fig. 14).
Details of these can be found in their
respective Product Data sheets.
DeltaTron® accelerometers require
Single Channel DeltaTron® Power

Line Drive Accelerometer Type
8318 and Underwater Accelerometer
Type 8319 have a built-in preamplifier,
but
require
Preamplifier
EQ 2126 and Power Supply EQ 2127
due to the line drive principle. Type
8318 can also be supplied as 8318/
WH 2146 with charge output.
Using charge preamplifiers, very
long connection cables can be used
without altering the specified sensitivity of the accelerometer and
preamplifier combination.
7

Since ease of calibration and measurement are usually just as important as overall gain and frequency
range, most Brüel & Kjær Preamplifiers have one or more of the following
signal conditioning aids:

own frequency response, sensitivity
and system calibration, Brüel & Kjær
manufacture the apparatus shown in
Fig. 15, for which separate Product
Data sheets are available.

Sensitivity Conditioning Networks
Allow direct dial-in of transducer sensitivity on the preamplifier, giving
unified system sensitivities.

Individual Brüel & Kjær
Accelerometer Types

Integration Networks
Automatically convert measured acceleration to a velocity and/or displacement proportional signal.
High- and Low-pass Filters
Permit selection of different lower
and upper frequency limits on the
preamplifier to exclude unwanted
signals and the influence of the accelerometer resonance from measurements.

Calibration
Factory Calibration
Brüel & Kjær
accelerometers are
thoroughly checked and examined at
all stages of manufacture and assembly. Each accelerometer undergoes an
extensive calibration procedure and
artificial ageing process so as to ensure completely predictable performance and stable operation. Accurate
numerical details of the calibration
are reported on the calibration chart
supplied with each transducer (see
Fig. 5).
Calibration of Brüel & Kjær Piezoelectric Accelerometers is by back-toback comparison with a primary reference standard accelerometer calibrated at the Danish Primary
Laboratory of Acoustics (DPLA), regularly checked by the American National Institute of Science and
Technology (NIST), the German
Physikalisch–Technische Bundesanstalt (PTB) for traceability. The overall accuracy of the back-to-back
comparison is 2% with a 99.9% confidence level (1.6% for a 99% confidence
level),
while
for
the
interferometry method the accuracy
is better than ± 0.6% with a 99% confidence level.
Subsequent Calibration
Regular calibration of accelerometers
helps maintain confidence in the
measurements taken and indicates
whether accelerometers have been
damaged. To help users perform their
8

Dimensions and specifications for the
accelerometers can be found in the
schemes given towards the end of
this Product Data sheet. In addition
to the general features so far described, some of these accelerometers
have been designed for more specialized applications, and the special features of these accelerometers are
discussed below.
Accelerometers with an Insulated
Base
Types 4391, 4391V and 4391E
See Fig. 16. Industrial Accelerometer
Type 4391V is also available as UniGain® Accelerometer Type 4391. The
Uni-Gain® version has a tolerance of
±2%. Both types are suitable for most
vibration measurement applications
and are certified intrinsically safe to
EEx ia IIA T4, T5 and T6. Intrinsically Safe Accelerometer Type 4391E
is a special version that is certified
intrinsically safe to EEx ia I/IIC T4,
T5 and T6.
The base of Types 4391/V/E is electrically insulated to prevent ground
loops which might otherwise distort
the vibration signal being measured.
The accelerometers are tested at
500 V and typically show that the resistance to ground loop effects is
50 M Ω.
Connection to other instruments is
made using a sturdy top mounted
TNC connector. A strong spiralwound mini-noise cable A0 0268 is
available for use with these accelerometers.

4397

4395

4398

4396

4399

Fig.17

DeltaTron® Accelerometers Types
4394, 4395, 4396, 4397, 4398 and 4399
The
DeltaTron®
accelerometers
(Fig. 17) are constructed to the proven Brüel & Kjær DeltaShear design
with the addition of an integral
preamplifier. They require an external constant-current power supply
and operate as voltage sources.
DeltaTron® accelerometers operate
over a frequency range from below
1 Hz to approximately half the resonance frequency of the accelerometer
assembly. They are available in two
forms, with or without an insulated
base. For further details see the separate Product Data sheet.
Triaxial Accelerometers Types 4321
and 4321V
Consist of three separate Delta
Shear® Accelerometers in a single
housing which are accurately aligned
so that vibration in three mutually
perpendicular directions can be
measured (Fig. 18).
Triaxial Accelerometer Type 4326
Type 4326 (Fig. 19) has three separate ThetaShear® accelerometers in
a miniature housing. Its size and
weight make it ideal for use in confined spaces or with delicate structures.
Type
4326
has
M3

4391, 4391V &
4391E

Fig.16

4394

4321 & 4321V

Fig.18

4374
8309
4326

Fig.19

Fig.21

Fig.23

subminiature connectors made of titanium.

Miniature Accelerometer Type 4374
This accelerometer (Fig. 21) has been
designed to measure the vibration of
very lightweight structures where
high level, high frequency vibration
signals are commonly encountered,
and where the use of heavier transducers would alter the mode of vibration, invalidating measurements.
Typical application areas are measurements on thin vibrating panels,
model testing, work in confined spaces and measurement of moderately
high level shock.
Type 4374 features a planar shear
construction, weighs 0.65 grams (excluding cable) and is suitable for
measurement at frequencies up to
26 kHz (10% limit). The accelerometer has an integral 32 to 40 cm long
connection cable with miniature coaxial plug attached, and has a plane
base for wax or cement mounting.

very light structures in preference to
Types 4393 and 4393 V.

High Sensitivity Line-drive
Accelerometer Type 8318
Type 8318 (Fig. 20) is a very high sensitivity DeltaShear® accelerometer
with a built-in line-drive preamplifier. The Uni-Gain® sensitivity is
316 µA/ms–2.
The high sensitivity of this accelerometer makes it suitable for measuring very low level vibrations over
a frequency range of 0.1 Hz to 1 kHz
(10% limit). With a third octave or
narrow band filter included in the
measuring arrangement, measurement of vibration levels down to
0.00002 ms–2 is possible. Principal
applications are in vibration investigations on large structures such as
buildings, bridges and ships. It is also
useful for seismic work.
Due to the line drive principle a
Preamplifier Type EQ 2126 and a
Power Supply EQ 2127 are required.
8318/WH 2146 is a special version of
8318 with charge output.
Connection to measuring instruments is made via a TNC connector,
and a 1.1 m long spiral TNC to TNC
cable is supplied with the accelerometer. The spiral cable can stretch to
approx. 4 m without being damaged.
For mounting the 8318, 16 mm long
M8 threaded steel studs are supplied
with the accelerometer as standard
accessories. Four self-adhesive mounting discs DU 0079 are also supplied.

8318

Fig.20

Miniature Accelerometers Types
4375, 4375V, 4393 and 4393V
These accelerometers (Fig. 22) are
suitable for measurements on lightweight structures where relatively
high level, high frequency vibrations
are found. The principal application
areas are similar to those of the Type
4374.
Types 4375, 4375 V, 4393 and
4393 V have a DeltaShear® construction. Types 4375 and 4393 are UniGain® types. All types weigh 2.4
grams (excluding cable), and can be
used for measurement of frequencies
up to 16.5 kHz (10% limit).
Types 4375 and 4375 V have an integral 32 to 40 cm long connection cable with miniature coaxial plug
attached. Types 4393 and 4393 V
have a sub-miniature coaxial socket
for cable connection. All accelerometer types have M3 screw threads for
stud mounting. Types 4375 and
4375 V are used for more permanent
vibration monitoring applications on

4393 &
4393V

Fig.22

Shock Accelerometer Type 8309
Accelerometer Type 8309 (Fig. 23) is
especially intended for measurement
of very high level continuous vibration and mechanical shock up to
150 kms–2 and 1000 kms–2 peak, respectively.
The 8309 is of a particularly sturdy
construction necessary for withstanding very high level continuous vibration and shock. Its PZ 45 piezoelectric
element is prepared and treated to
withstand very high dynamic stress
with negligible problems of “zero
shift”. Type 8309 has an integral 32
to 40 cm long output cable, which
gives the advantage of a reliable output connection at very high shock levels.
For rigid mounting, the base of the
8309 has an integral M5 threaded fixing stud which is adequately dimensioned to transmit the full motion of
the test object to the piezoelectric element without distortion.

What to Order
Uni-Gain® accelerometers available
from Brüel & Kjær can be supplied in
the form of a Set. An Accelerometer Set (suffix S after type number)
consists of a single accelerometer
complete with cable and a range of
accessories in a mahogany case such
as shown in Fig.16.
Accelerometer Type 8318 is supplied only as an Accelerometer Set.

4375 &
4375V

Fig.24 Accelerometer set

9

Standard Accessories
Brüel & Kjær
Part No.

Standard Accessories
S model includes accessory set (UA xxxx)
in addition to standard accessories (–):

4370/1
4381/2/3/4
4370V/1V
4381V/2V/
3V/4V

4321
4321V

UA 0078

UA0146

–

–

1*

3*

4326

AO 0038

AO 0231

260°C (500°F) Teflon® super-low-noise cable,
AC 0005 fitted with one 10 –32 UNF connector
and one TNC connector. Length 3 m (10 ft)

AO 0268

85°C (185°F) spiralized low-noise cable,
AC 0205 with polyurethane jacket, fitted with
TNC connectors. Length 1.1 to 4m.
Spiral ∅ 12.5 mm.

AO 0283

260°C (500°F) Teflon® super-low-noise cable,
AC 0205 (∅ 1.5 mm) fitted with 10– 32 UNF
and M 3 connectors. Length 1.2 m (4 ft)

3*

UA 1243

3 × 30 pcs. of red/green/yellow cable markers

1*

JJ 0032

Extension connector for Brüel & Kjær cables
fitted with 10–32 UNF connectors JP 0012

JP 0162

10–32 UNF to TNC connector adaptor

YQ 2960

10–32 UNF threaded steel stud. Length 0.5 in.
10–32 UNF insulated stud. Length 0.5 in.

YQ 2007

M3 threaded steel stud. Length 8 mm

YQ 2003

M3 threaded steel stud. Length 5 mm

YQ 9335

M8 steel stud. Length 16 mm

DB 0756

Cement stud 10–32 UNF. ∅ 14 mm

DB 2790

Cement stud 10–32 UNF. ∅ 25 mm

DB 0757

Cement stud M3. ∅ 8 mm

8318

–

–

1

1†

–

–

8309

UA0415

–

1

–
1

1

1‡

1
1
1

4

3
1

1

3

1†

1

3

1

1

5

1
1

3

1

1

3
1

5
1

3*

2
1

3
4

1

1

1
1
2

Mounting magnet & 2 insulating discs DS 0553

UA 1077

Small mounting magnet & 2 insulating discs
DS 0786

DU 0079

1 × adhesive mounting disc. ∅ 40 mm

YO 0073

25 × adhesive mounting disc. ∅ 5.5 mm

QS 0007

Tube of cyanoacrylate adhesive

YJ 0216

Beeswax for mounting

1

1

YO 0534

Insulating mica washer ∅ 15, ∅ 5 mm

1

1

YO 0746

Insulating mica washer ∅ 25, ∅ 5 mm

QA 0029

Tap for 10–32 UNF thread

1

1

QA 0041

Tap for M3 thread

QA 0068

Tap for M5 thread

QA 0141

Tap for M8 thread

QA 0013

Hexagonal key for 10 –32 UNF studs

QA 0042

Hexagonal key for M3 studs

QA 0038

Hexagonal key for M4 studs

QA 0121

Hexagonal key for M8 studs

QA 0220

Cable connecting/removal tool

YM 0334

M3 nut

YM 0414

10–32 UNF nut

YQ 0093

M4 threaded steel screw. Length 16 mm

YQ 8941

M2 × 10 steel screw

YP 0080
DB 0544

Probe with sharp tip. 10–32 UNF
Round tip

10

4378
4379

1

UA 0642

1

1

1

1
4
1

1

1

1

1

1

1

1

1

1*
5
1

1

1
1
1
1

1

1
1*

1

1

1
1
1*
1
1

1
1

1

1
3*

1

Individual calibration chart

1

1

Individual frequency response curve

1*

1*

* Only for types with no suffix (“V”, “A” and “E” types)
† Only Type 4375
‡ Only Type 4393

4375
4391
4375V
4391V
4393
4391E
4393V

UA1079 UA0629 UA0844 UA0856

–

260°C (500°F) Teflon® super-low-noise cable,
AC 0005 (∅ 2 mm) fitted with 10 –32 UNF
connectors JP 0012. Length 1.2 m (4 ft)

YP 0150

4374

1

1

1

1

1

1

1*

1

1

1

DeltaTron® Accessories
Brüel & Kjær
Part No.

Standard Accessories
S model includes accessory set (UA xxxx)
in addition to standard accessories (–):

4394

4395

4396

4397

4398

4399

UA1218

UA1219

UA1219

UA1218

UA1219

UA1219

–

AO 1381

Teflon low-noise cable, double screened AC 0104 (∅ 1.6 mm).
Fitted with 10–32 UNF and M3 connectors. Length 1.2 m (4 ft)

AO 1382

Teflon low-noise cable, double screened AC 0104 (∅ 1.6 mm).
Fitted with 10–32 UNF connectors. Length 1.2 m (4 ft)

–

–

–

1

1

–

–

1

1

1
1

1

JJ 0032

Extension connector for cables fitted with 10– 32 UNF connectors

3

3

3

3

3

3

JP 0145

10–32 UNF to BNC connector adaptor

1

1

1

1

1

1

YS 8321

Steel stud M3/M3 (UA 1221 is a set of 25 of these studs)

3

YQ 2003

Steel Stud M3, 5 mm long

YQ 2960

10–32 UNF threaded steel stud. Length 0.5 in.

2

2

2

2

YQ 2962

10–32 UNF threaded steel stud. Length 0.3 in.

3

3

3

3

DB 0757

Cement stud M3. ∅ 8 mm

3

1

1

DB 0756

Cement stud 10–32 UNF. ∅ 14 mm

YG 0150

Steel stud 10 – 32 UNF/10 – 32 UNF with flange

UA 0642

Mounting magnet & 2 insulating discs DS 0553

YJ 0216

Beeswax for mounting

1

YO 0073

25 × adhesive mounting disc. ∅ 5.5 mm

1

QS 0007

Tube of cyanoacrylate adhesive

1

1

QA 0041

Tap for M3 thread

1

1

1
1

2

1
1

1

2

1

1

1

1

1
1

2

1
1

2

1

1

1

1

1

1
1

1

QA 0029

Tap for 10–32 UNF thread

QA 0042

Hexagonal key for M3 studs

1

1

QA 0013

Hexagonal key for 10 –32 UNF studs

1

1

1

YM 0414

10–32 UNF nut

1

1

1

BC 0200

Individual calibration chart

1

1

1

1

1

1

Individual frequency response curve

1

1

1

1

1

1

1

1
1

Cable Assembly Overview
Standard
Cable 6)

Accelerometer
Connector

Extension
Connector

Plug

Customer Assembled Cable
Free-length Cable
Plug

Adaptor

Front-end
Connector

AO 0283
M3
(Female)

AO 0339

10 – 32 UNF
AO 0066

AO 1381

AO 0104
10 – 32 UNF
(Male)

JJ 0207

2-pin TNC

JP 0145

BNC

AO 0205
AO 0038

JP 0032 3)

JP 0012 1)

JP 0012

1)

AO 0005

JJ 0032 3)
AO 0122

AO 0208

AO 0463
AO 0406 5)

JP 0056 2)

AO 0200

JP 0056 2)

AO 1419
10 – 32 UNF
(Female)

AO 1382

JP 0162

AO 0231

AO 0231
UA 0641 4)
TNC
(Female)

TNC

AO 0193
AO 0268

JJ 0175

960335e

1) Available in set with 25 pcs. as UA 0130
2) Available in set with 25 pcs. as UA 0730
3) Available in set with 25 pcs. as UA 0186

4) For accelerometers with top connector
5) AO 0406 includes JP 0145
6) See also table on last page

11

Additional Accessories Available

JJ 0175: Extension connector for
TNC to TNC cable. JJ 0207: 2-pin
TNC to 10–32 UNF plug adaptor.
JP 0145: 10–32 UNF to BNC plug
adaptor. JP 0162: 10–32 UNF to TNC
plug adaptor. UA 0641: 10–32 UNF to
BNC extension connector for accelerometers with top connector.

UA 0643: Set of 5 10–32 UNF mounting magnets UA 0642, ∅ 24.45 mm.
Includes PTFE self adhesive discs
DS 0553 for electrical insulation.
UA 1075: Set of 5 UA 1077, M3
∅ 10.2 mm. Includes PTFE self adhesive discs DS 0786 for electrical insulation.

UA 0130: Set of 25 plugs JP 0012 for
cable AC 0104 and AC 0005.
UA 0730: Set of 25 plugs JP 0056 for
cable AC 0200. For mounting the
plugs, the assembly tool QA 0035 is
required.

QA 0035: Assembly tool for mounting
miniature plugs on accelerometer cables.

UA 0186: Set of 25 extension connectors JJ 0032 for miniature cables with
plugs JP 0012 and JP 0056.

UA 1221: Set of 25 M3/M3 steel studs
YS 8321.

UA 1192: Set of 10 10–32 UNF/
10–32 UNF insulating studs UA 1215
UA 1193: Set of 10 M3/M3 insulating
studs UA 1216.

UA 0866: Set of 25 10–32 UNF cement studs DB 0756
UA 0867: Set of 25 M3 cement studs
DB 0757.

UA 0125: Set of 10 insulating studs
YP 0150, 10 steel studs YQ 2960, 10
nuts YM 0414, 10 mica washers
YO 0534 plus 10–32 UNF tap and
hexagonal key for 10–32 UNF studs.

UA 0553: Set of 5 electrically insulated Mechanical Filters UA 0559, plus
a tommy bar for mounting. Also available with M3 thread as WA 0224 (only
1 pc.).

UA 1243: 3 × 30 red/green/yellow cable markers for AC 0205/AC 0104
UA 1244: 3 × 30 red/green/yellow cable markers for AC 0005/AC 0208.

BB 0694: Piezoelectric Accelerometers and Vibration Preamplifiers,
Theory and Application Handbook.

12

Accelerometer Dimensions

All dimensions in mm

Types 4321 & 4321V

Types 4391 & 4391V

Type 4326
Type 4326

Type 4326 has M3 sub-miniature connectors

Types 4375 & 4375V

Types 4393 & 4393V

Centre of gravity: “o” seismic mass — “x” whole assembly

13

Accelerometer Dimensions
Types 4371 & 4371V

All dimensions in mm
Types 4378 & 4378V

Types 4384 & 4384V

841391/1e

Types 4382 & 4382V

Types 4383 & 4383V

841531/2e

Types 4381 & 4381V

Centre of gravity: “o” seismic mass — “x” whole assembly

14

Types 4370 & 4370V

DeltaTron® Accelerometer Dimensions

All dimensions in mm

Centre of gravity: “o” seismic mass — “x” whole assembly

15

Specifications1
4375
4375V

Weight

grams

Charge Sensitivity for Uni-Gain®DeltaShear® types2, 5
Voltage Sensitivity for Uni-Gain®DeltaShear® types5
Charge Sensitivity for DeltaShear®
“V” types

−2

pC/ms
pC/g

mV/ms
mV/g

pC/ms−2
pC/g
mV/ms

Voltage Sensitivity for DeltaShear®
“V” types

mV/g

Mounted Resonance5,

kHz

Frequency Range5, 6,

6

−2

−2

5% Hz

9

Max. Transverse Sensitivity1, 5,

8

Transverse Resonance

Magnetic Sensitivity
(50 Hz – 0.03 T)

4382
4382V

4391
4391V

4383
4383V

4370
4370V

4381
4381V

2.410

11

16

17

0.316 ± 2%

1 ± 2%

1 ± 2%

3.16 ± 2%

10 ± 2%

3.1 ± 2%

9.8 ± 2%

9.8 ± 2%

31 ± 2%

98 ± 2%

0.48

0.8

0.8

2.6

8

4.8

8

8

26

80

0.3 ± 15%

1 ± 15%

1 ± 15%

3 ± 15%

10 ± 15%

3 ± 15%

10 ±15%

10 ± 15%

31 ± 15%

98 ± 15%

0.5

0.8

0.8

2.6

8

5

8

8

26

80

55

42

40

28

16

0.2 – 12 000

0.2 – 9100

0.2 – 8700

0.2 – 6100

0.2 – 3500

4

54

43

0.1 – 12 600

0.1 – 12 000

0.1 – 8400

0.1 – 4800

650

1200

1200

1200

1200

%

<4

<4

<4

<4

<4

kHz

18

15

12

10

4

PZ 23

PZ 23

PZ 23

PZ 23

PZ 23

DeltaShear

DeltaShear

DeltaShear

DeltaShear

DeltaShear

ms−2/µε

0.005

0.02

0.005

0.01

0.003

g/µε

0.0005

0.002

0.0005

0.001

0.0003

Construction

Temperature Transient Sensitivity
(3Hz LLF, 20dB/decade)

4371
4371V

0.1 – 16 500

Piezoelectric Material

Base Strain Sensitivity
(in base plane at 250 µε)

4384
4384V

pF

10% Hz
Capacitance5, 7

4393
4393V

−2

ms /°C

5

0.4

0.2

0.1

0.02

0.04

0.28

0.022

0.011

0.0056

0.0011

0.0022

ms−2/T

30

4

4

1

1

g/kGauss

0.3

0.04

0.04

0.01

0.01

0.04

0.01

0.01

0.002

0.001

0.004

0.001

0.001

0.0002

0.0001

g/°F

−2

Acoustic Sensitivity
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)

ms

Min. Leakage Resistance at 20°C

GΩ

20

20

20

20

20

°C

–74 to 250

–74 to 250

–60 to 180

–74 to 250

–74 to 250

250

200

20

50

20

25000

20000

2000

5000

2000

50

60

20

20

20

Ambient Temperature Range
Max. Operational Shock (± Peak)

g

kms−2
g

Max. Operational Continuous
Sinusoidal Acceleration (Peak)
Max. Acceleration (Peak) with
mounting magnet

Base Material

1
2
3
4
5
6

16

kms

−2

g

5000

6000

2000

2000

2000

kms−2

–

1.5

1.2

1.2

0.6

g

–

150

120

120

60

Titanium
ASTM Gr. 2

Titanium
ASTM Gr. 2

Titanium
ASTM Gr. 2

Titanium
ASTM Gr. 2

Data obtained in accordance with ANSI S2. 11-69 and ISO/DIS 5347
Uni-Gain measured sensitivity adjusted to ±2%
Built-in Line-drive preamplifier. Sensitivity in µA/ms-2
Local resonances of up to ±1.5 dB permitted
Individual specifications given on the calibration chart for Uni-Gain types
Individual curves not supplied with 4375, 4393, 4374, 4321 and 8309 or
DeltaShear“V” types

7
8
9

Steel
AISI 316

Titanium
ASTM
Gr. 2

With cable supplied as standard accessory, or integral cable
Axis of minimum transverse sensitivity indicated for Uni-Gain types (except 4321, 4374,
8309)
The low frequency cut-off is determined by the preamplifier and environmental conditions

Note: All values are typical at 25°C (77°F), unless measurement uncertainty or
tolerance field is specified. All uncertainty values are specified at 2σ (i.e. expanded
uncertainty using a coverage factor of 2)

Specifications1
4378
437415

4321
4321V

4326

8318

8309

175

470

0.6510)

55

10

310

pC/ms−2

31.6 ± 2%

–

–

1 ± 2%

–

–

pC/g

310 ± 2%

–

–

9.8 ± 2%

–

–

26

316 ± 2%3

–

0.8

–

–

–

8

–

–

4379
Weight

grams

Charge Sensitivity for Uni-Gain®DeltaShear® types2, 5
Voltage Sensitivity for Uni-Gain®DeltaShear® types5
Charge Sensitivity for DeltaShear®
“V” types

mV/ms−2
mV/g
pC/ms

260
−2

pC/g
−2

3100

3

–

–

0.11

1 ± 15%

0.3

0.004

–

–

1.1

9.8 ± 15%

3

0.04

Voltage Sensitivity for DeltaShear®
“V” types

mV/ms

–

–

0.18

0.8

–

0.04

mV/g

–

–

1.8

8

–

0.4

Mounted Resonance5,

kHz

13

6.5

85

40

X: 40, Y: 30,
Z: 50 kHz

180

5% Hz

0.2 – 2800

10% 0.1
– 100014)

1 – 18 500

0.2 – 870011)

-

1– 39 000

10% Hz

0.1 – 3900

3dB 0.06 –
125014)

1 – 26 000

0.1–
12 00011

3 Hz to
X: 13.3, Y: 10,
Z: 16.6 kHz

1 – 54 000

Frequency

6

Range5, 6, 9

Capacitance5, 7
Max. Transverse Sensitivity1, 5,

8

Transverse Resonance

pF

1200

–

600

1200

1000

100

%

<4

<5

<5

<4

<5

<5

kHz

3.8

1.6

21

14

X: 18, Y: 18,
Z: 20 kHz

28

PZ 27

PZ 23

PZ 27

PZ 23

PZ 23

PZ 45

DeltaShear

DeltaShear

Planar
Shear

DeltaShear

ThetaShear

CentreMount.
Compression

0.002

0.0003

0.005

0.02

0.055

2

0.0002

0.000 03

0.0005

0.002

0.0055

0.2

0.001

0.0001

10

0.4

1

400

0.000 056

0.000 005 6

0.56

0.022

0.056

22

0.5

1

30

4

12

20

g/
kGauss

0.005

0.01

0.3

0.04

0.12

0.2

ms−2

0.001

0.001

0.1

0.01

0.035

4

0.0001

0.0001

0.01

0.001

–

0.4

Piezoelectric Material
Construction
Base Strain Sensitivity
(in base plane at 250 µε)
Temperature Transient Sensitivity
(3Hz LLF, 20dB/decade)

ms−2/µε
g/µε
ms−2/°C
g/°F
−2/T

ms
Magnetic Sensitivity
(50 Hz – 0.03 T)
Acoustic Sensitivity
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)

g

Min. Leakage Resistance at 20 °C

GΩ

20

–

20

20

10

20

Ambient Temperature Range

°C

– 40 to 250

– 50 to 85

–74 to 250

–74 to 250

–55 to 175

–74 to 180

5

0.01512

250

10

30

1000

25 000

1000

3000

100 000

kms−2
Max. Operational Shock (±Peak)
g
Max. Operational Continuous
Sinusoidal Acceleration (Peak)
Max. Acceleration (Peak) with
mounting magnet
Base Material
10
11
12

12

500
−2

1.5

12

50

5

–

150

g

500

1.512

5000

500

–

15 000

kms−2

0.2

–

–

0.6

–

–

g

20

–

–

60

–

–

Stainless Steel
AISI316

Stainless Steel
AISI 303

Beryllium13

Titanium
ASTM Gr. 2

Aluminium case,
titanium sockets

Stainless
Steel AISI316

kms

5

Excluding cable
The transverse resonance frequency may limit the useful frequency range
further
Measurement limits. Handling limits given in the Dynamic Range section (pages
4 and 5)

0.015

13
14
15

Toxic hazard in finely divided form
Including Preamplifier EQ 2126 and Power Supply EQ 2727
4374 Pat. USA 4211951, DK 138768 and GB 1522785. DeltaShear Pat. DK 131401

17

Specifications
Common to Both Types of DeltaTron® Accelerometer
Type 4394
Type 4397

1.00
(9.807) ±2 %

10.0
(98.07) ±2 %

temperature <100°C (212°F)

ms−2 (g)

±7 500 (765)

±750 (76)

temperature < 125°C (257°F)

ms−2

±5 000 (510)

±500 (51)

(g)

Frequency Range (±10%)

Hz

Maximum Transverse Response

%

<4

temperature <100°C (212°F)

mA

+ 2 to +20

temperature <125°C (257°F)

mA

for full specification

V DC

+24 to +30

minimum (reduced specification)

V DC

+18

W

<100

at 25°C (77°F), 4 mA

V

12 ±0.5

full temperature and current range

V

8 to 15

from 1 to 22000 Hz

µV

Constant Current Supply

1 to 25000

Output Impedance

equivalent acceleration

ms

−2

(g)

<25

<15

<40

<0.025 (0.0026)

<0.015 (0.0015)

<0.004 (0.0004)

Polarity (acceleration directed from base into body)
Recovery time from Overload (2 × maximum level)

Positive
µs
−2

Axial

ms

Transverse

ms−2

Temperature Range

<20

<15

<25

(g)

100000 (10200)

50000 (5100)

20000 (2040)

(g)

50000 (5100)

20000 (2040)

10000 (1020)

°C (°F)

−50 to +125 (−58 to +257)

Humidity

Welded, sealed
ms−2/°C

Temperature Transient Sensitivity
g/°F
−2

Magnetic Sensitivity (50 Hz, 0.038 T)

ms (g)/ T

Acoustic Sensitivity (154 dB SPL)

ms−2

(g)

2

0.2

0.1

0.11

0.011

0.0056

10 (1)

20 (2)

5 (0.5)

0.01 (0.001)

0.005 (0.0005)

0.002 (0.0002)

Construction

DeltaShear

Piezoelectric Material
Case Material
Connector
Mounting Thread
Mounting Torque

18

1 to 14000

+2 to +20

Bias Voltage

Residual Noise

0.3 to 18000

+2 to +10

Supply Voltage, unloaded

Maximum Non-destructive
Shock (peak)

Type 4396
Type 4399

mV/ms−2
(g)

Sensitivity (axial) at 159.2 Hz, 100 ms−2 (10.2g), 25°C (77°F), 4 mA

Measuring Range (peak)

Type 4395
Type 4398

PZ 23
Titanium
Coaxial
Tapped center-hole
Nm (lb.in)

ASTM Gr. 2
M3 miniature

10–32 UNF

M3

10–32 UNF

0.2 to 0.6
(1.8 to 5.3)

0.5 to 3.5 (4.4 to 31)

Specifications
DeltaTron® — Insulated Base
4394

4395

4396

Mounted Resonance Frequency

kHz

52

37

28

Transverse Resonance Frequency

kHz

15

13

9

Case Insulation to Ground

>10

MΩ
−2

Base Strain Sensitivity

ms (g) /µε

0.005 (0.0005)

0.01 (0.001)

0.005 (0.0005)

Weight

gram (oz.)

2.9 (0.10)

12.9 (0.46)

18.2 (0.64)

Height

mm (in)

14.0 (0.55)

21.7 (0.85)

23.7 (0.93)

Spanner Size

mm (in)

8.0 (0.31)

14.0 (0.55)

15.0 (0.59)

4397

4398

4399

Specifications
DeltaTron® — Uninsulated Base
Mounted Resonance Frequency

kHz

53

38

29

Transverse Resonance Frequency

kHz

17

14

10

Base Strain Sensitivity

ms−2(g) /µε

0.005 (0.0005)

0.02 (0.002)

0.01 (0.001)

Weight

gram (oz.)

2.4 (0.09)

11.8 (0.45)

17.1 (0.63)

Height

mm (in)

12.4 (0.49)

19.7 (0.77)

21.7 (0.85)

Spanner Size

mm (in)

7.5 (0.30)

14.0 (0.55)

15.0 (0.59)

Specifications for Cables for Use With Standard
Accelerometers
AC 0005

AC 0066

AC 0104

AC 0200

AC 0205

AC 0208

–75 to + 250

–75 to + 250

–50 to + 100

–75 to + 250

–75 to + 250

Moveable: – 5 to +70
Fixed: –20 to +70

Noise

Super low
noise

Low noise

Low noise

Super low
noise

Super low
noise

–

Insulator material/Coating

PTFE/PFA

PTFE/PFA

PTFE/PFA

PTFE/PFA

PTFE/PFA

PE/PVC

Single

Single

Double

Double

Single

Single

106

95

105

95

100

100

Ø 2.0

Ø 1.0

Ø 1.6

Ø 3.2

Ø 1.5

Ø 2.0

JP 0012

JP 0012

JP 0012

JP 0056

JP 0012

JP 0012

Temperature (°C)

Screen
Capacitance (pF/m)
Dimension (mm)
10 – 32 plug for self-mounting

19

Specifications for
Reference and
Underwater
Accelerometers
Weight

grams

Charge Sensitivity for DeltaShear®
“V” types

pC/ms−2

Cables with and without connectors
Free-length Cable
Length
Type
(m)

8305
83192
40

44
(with 0.15 m cable)

0.12 4

–

4

pC/g

1.2

AC 0005

–

µA/ms−2

–

µA/g

–

9.8 ± 2%3, 4

kHz

30 (with 20 g load)4

> 35

Frequency Range7

Hz

0.2 – 3100 (1%)4
0.2 – 4400 (2%)4

0.3 – 11 000 (10%)

Capacitance 5

pF

180

–

Max. Transverse Sensitivity

%

<2 4, 6

<4

Transverse Resonance

kHz

–

14

Quartz

PZ 23

Inverted Centre
Mounted Comp.

DeltaShear

ms−2/ µε

Top: 0.01
Base: 0.003

0.01

g/µε

Top: 0.001
Base: 0.0003

0.001

2

®

Current Sensitivity Uni-Gain
Line Drive types
Mounted Resonance

Piezoelectric Material
Construction

Sensitivity1

Base Strain
(in base plane at 250 µε)

−2

ms / °C

1 ± 2%3,

4

AC 0200

Connector
Type

3
1.2
1.2
3
5
10
30

10–32 UNF/TNC
TNC/TNC
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF

x

10–32 UNF/10–32 UNF

30
50
100
200
3
5
10
30

10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF

x

10–32 UNF/10–32 UNF

30
100
200
1.2
1.2
3
5
5
10
30

M3/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF*
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF

0.5

1

0.028

0.056

1

7

x

10–32 UNF/10–32 UNF

g/kGauss

0.01

0.07

Acoustic Sensitivity1
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)

ms−2

0.008

0.01

g

0.0008

0.001

Min. Leakage Resistance at 20°C

GΩ

1000
(10 at 200°C)

–

Ambient Temperature Range

°C

–74 to +200

–50 to + 100

30
100
1.2
3
5
10
30

10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF
10–32 UNF/10–32 UNF

10

20 (axial)

x

10–32 UNF/10–32 UNF

1000

2000 (axial)

10

–

1000

–

1

–

100

–

200
1.2
3
5
10
30

M3/10–32 UNF
M3/10–32 UNF
M3/10–32 UNF
M3/10–32 UNF
M3/10–32 UNF

Stainless Steel
AISI316

Stainless
UHB 904L

Temperature Transient Sensitivity1
(3Hz LLF, 20dB/decade)
Magnetic Sensitivity1
(50 Hz – 0.03 T)

Max. Operational Shock (± Peak)1
Max. Operational Continuous
Sinusoidal Acceleration (Peak)
Max. Acceleration (Peak) with
mounting magnet

g/°F
ms−2/T

kms−2
g
kms−2
g
kms−2
g

Base Material
1
2
3
4
5
6
7

AC 0104

AC 0208

Data obtained in accordance with ANSI S2. 11-69 and ISO/DIS 5347
Uni-Gain measured sensitivity adjusted to ±2%
Built-in Line-drive preamplifier
Individual specifications given on the calibration chart
With integral cable supplied as standard
Axis of minimum transverse sensitivity indicated
The low frequency cut-off is determined by the preamplifier and environmental conditions

AC 0205

AC 0066

Spiral
Brüel&Kjær reserves the right to change specifications and accessories without notice

Brüel & Kjær

B

x

M3/10–32 UNF

30
100
1.2
1.2

10–32 UNF/10–32 UNF
M3/10–32 UNF

x

M3/10–32 UNF

30
1.1 – 4

TNC –TNC

Order No.
AO 0231
AO 0193
AO 0038
AO 038F
AO 0038G
AO 0038H
AO 0038K
AO 0038VAC 0005-x
AC 0005K
AC 0005L
AC 0005M
AC 0005N
AO 0122
AO 0122G
AO 0122H
AO 0122K
AO 0122VAC 0200-x
AC 0200K
AC 0200M
AC 0200N
AO 1381
AO 1382
AO 1382F
AO 1382G
AO 0406
AO 1382H
AO 1382K
AO 1382VAC 0104-x
AC 0104K
AC 0104M
AO 0463
AO 0463F
AO 0463G
AO 0463H
AO 0463K
AO 0463VAC 0208-x
AC 0208N
AO 0283
AO 0283F
AO 0283G
AO 0283H
AO 0283K
AO 0283VAC 0205-x
AC 0205K
AC 0205M
AO 1419
AO 0339
AO 0339VAC 0066-x
AO 0066K
AO 0268

* Includes 10–32 UNF/BNC Adaptor JP 0415

K

WORLD HEADQUARTERS:
DK-2850 Naerum · Denmark · Telephone: +45 45 80 05 00 · Fax: +45 45 80 14 05 · Internet: http://www.bk.dk · e-mail: info@bk.dk
Australia (02 ) 9450-2066 · Austria 00 43-1-865 74 00 · Belgium 016/44 92 25 · Brazil (011) 246-8166 · Canada: (514) 695-8225 · China 10 6841 9625 / 10 6843 7426
Czech Republic 02-67 021100 · Finland 90-229 3021 · France (01) 69 90 69 00 · Germany 0610 3/908-5 · Holland (0)30 6039994 · Hong Kong 254 8 7486
Hungary (1) 215 83 05 · Italy (02) 57 60 4141 · Japan 03-3779-8671 · Republic of Korea (02) 3473-0605 · Norway 66 90 4410 · Poland (0-22) 40 93 92 · Portugal (1) 47114 53
Singapore (65) 275-8816 · Slovak Republic 07-37 6181 · Spain (91) 36810 00 · Sweden (08) 71127 30 · Switzerland 01/94 0 09 09 · Taiwan (02) 713 9303
United Kingdom and Ireland (0181) 954-236 6 · USA 1 - 800 - 332 - 2040
Local representatives and service organisations worldwide

BP 0196 – 20

97/01



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Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.2
Linearized                      : Yes
Create Date                     : 1997:07:22 10:04:24
Producer                        : Acrobat Distiller 3.0 for Windows
Creator                         : FrameMaker 5.1.1P2c
Title                           : Product Data Sheet: Piezoelectric DeltaShear® Accelerometers, Uni-Gain® , DeltaTron® and Special Types
Modify Date                     : 1997:07:22 10:28:03
Page Count                      : 20

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