Product Data Sheet BRK_4375 BRK 4375

User Manual: BRK_4375

Open the PDF directly: View PDF PDF.
Page Count: 20

Product Data
Brüel & Kjær
BK
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:
❍Shock and vibration measurement and analysis
❍Vibration monitoring
❍Modal and structural analysis
❍Vibration test control
❍Production and quality control
FEATURES:
❍Competitively priced DeltaShear® “V” Types,
especially suitable for permanent set-ups
❍Uni-Gain® types for easy interchangeability
❍DeltaTron® and Line-drive types with integral
preamplifer
❍Acceleration ranges cover 20µms–2 to 1000 kms–2
❍Frequency ranges cover from a fraction of a Hz to
60 kHz (+10% limit)
❍Temperature ranges cover –74°C to +250°C (–101
to +482°F)
❍Low sensitivity to extraneous environmental
influences including temperature fluctuations
❍Low sensitivity to base bending effects
❍Individual calibration supplied
❍Artificially aged for long term stability
4379
4378
4381
4381V
4370
4379V
4382
4382V
4383
4383V
4391
4391V
8318
4371
4371V
4384
4384V
4393
4393V
4375
4375V
4374
8309
4321
4321V
4394 4395 4396
4397 4398 4399 4326
8305
8319
2
tivity, are typical. In contrast the sen-
sitivity and other parameters for the
Uni-Gain® accelerometers are guar-
anteed within tight tolerances for
easy interchangeability without rec-
alibration (see specifications on page
16 and 17). Except for the sensitivity,
everything in this Product Data ap-
plies to both types.
Uni-Gain® Sensitivity
This designation indicates that the
measured accelerometer sensitivity
has been adjusted during manufac-
ture to within 2% of a convenient val-
ue, for example (in 10dB steps) 1,
3.16 or 10pC/ms–2.
Design and Construction
All the accelerometers except Types
4321, 4321V and 4326 measure
uniaxial acceleration. These types
measure accelerations in three mutu-
ally perpendicular directions.
With the exception of Triaxial Ac-
celerometer Type 4326, Miniature Ac-
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 piezoelectric elements of most
of the accelerometers are PZ23 lead
zirconate titanate elements. The
Shock Accelerometer Type 8309 has
a specially formulated ferroelectric
ceramic PZ45. The Miniature Accel-
erometer Type 4374 and the High
Sensitivity Accelerometers Types
4378 and 4379 have a lead zirconate
titanate element PZ27.
The housing material of all the ac-
celerometers is the same as the base
material (given in the Specifications)
except Type 4374, which has an nick-
el-chromium alloy housing.
The active element of Brüel&Kjær
accelerometers consists of piezoelec-
tric discs or slices loaded by seismic
masses and held in position by a
clamping arrangement. When the ac-
celerometer is subjected to vibration,
the combined seismic mass exerts a
variable force on the piezoelectric el-
ement. Due to the piezoelectric effect,
this force produces a corresponding
electrical charge.
For frequencies from DC up to ap-
proximately one third of the reso-
nance frequency of the accelerometer
assembly, the acceleration of the seis-
mic mass is equal to the acceleration
of the whole transducer. Consequent-
ly, the charge produced by the piezo-
electric element is proportional to the
acceleration to which the transducer
is subjected.
The electrical signal output from
Brüel&Kjær Accelerometers is self-
generated, though the types with
built-in preamplifiers require an ex-
ternal 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 Speci-
fications.
“V” and Uni-Gain® Types
Some of the piezoelectric accelerome-
ters described in this Product Data
sheet are available both as “V” types
as well as Uni-Gain® types. The Del-
taShear® 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 sensi-
Fig.1 The unique Brüel&Kjær Del-
taShear design. M=Seismic Mass,
P=Piezoelectric Element, B=base and
R=Clamping Ring
Fig.3 Comparison and PlanarShear designs. M=Seismic Mass, P=Piezoelectric Ele-
ment, B=Base, R=Clamping Ring and S=Spring
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 industri-
al use and transducers specifically de-
signed 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 respec-
tive Product Data sheets.
Fig.2 All DeltaShear® “V” types are sup-
plied in a robust plastic box
3
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 accelera-
tion (e.g. pC/ms–2) or in terms of volt-
age per unit acceleration (e.g. mV/
ms–2).
The sensitivities given in the indi-
vidual Calibration Charts have been
measured at 160Hz with an acceler-
ation of 100ms–2. For a 99.9% confi-
dence level the accuracy of the
factory calibration is ±2% and in-
cludes the influence of the connecting
cable supplied with each accelerome-
ter. With the exception of Triaxial Ac-
celerometers Types 4321, 4321V and
4326, the direction of main axis sen-
sitivity for these accelerometers is
perpendicular to the base plane of the
accelerometers. Types 4321, 4321V
and 4326 have three mutually per-
pendicular axes of sensitivity.
DeltaShear® Accelerometers
The Delta design involves three pie-
zoelectric elements and three masses
arranged in a triangular configura-
tion around a triangular centre post,
as illustrated in Fig.1. The Delta
Shear® design gives a high sensitiv-
ity-to-mass ratio compared to other
designs, a relatively high resonance
frequency and high isolation from
base strains and temperature tran-
sients. The excellent overall charac-
teristics of this design make it ideal
for both general purpose accelerome-
ters and more specialized types.
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 Delta-
Tron® accelerometers are individual-
ly calibrated Uni-Gain® types.
Line-drive Accelerometers
High Sensitivity Line Drive Acceler-
ometer Type 8318 and Underwater
Accelerometer Type 8319 have built-
in preamplifiers and operate accord-
ing to the principle of current modu-
lation (constant voltage supply). The
Line-drive principle allows cable
lengths of up to 1km.
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
851205/2e
Lower Frequency
Limit Sensitivity
pC/ms–2 Upper Frequency
Limit
Type no.
0.1 0.2 0.5 1.0 Hz 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
4321 1 ± 2%
4370, 4381 10 ± 2%
4371, 4384 1 ± 2%
4374 ≅ 0.11
4375, 4393 0.316 ± 2%
4378, 4379 31.6 ± 2%
4382, 4383 3.16 ± 2%
4391
8309
8318
1 ± 2%
≅ 0.004
316 ± 2%
4326 0.3 YYXXZZ
4396, 4399 10 ± 2%†
4395, 4398 1 ± 2%†
4394, 4397 1 ± 2%†
Fig.5 Example of the calibration chart supplied with the Brüel&Kjær accelerometers, together with a frequency response curve
4
Transverse Sensitivity
Accelerometers are slightly sensitive
to acceleration normal to their main
sensitivity axis. This transverse sen-
sitivity is measured during the facto-
ry calibration process using a 30Hz
and 100ms–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 reso-
nance frequency to give errors of less
than 10% and 5% respectively. These
calculations assume that the acceler-
ometer is properly fixed to the test
specimen, as poor mounting can have
a marked effect on the mounted res-
onance frequency.
The low-frequency response of an
accelerometer depends primarily on
the type of preamplifier used in the
measurement set-up. A detailed dis-
cussion of the effects of the measur-
ing system on the low-frequency
response of an accelerometer is given
in the Brüel&Kjær “Piezoelectric Ac-
celerometers and Vibration Preampli-
fiers Handbook”.
Line-drive Accelerometer Type
8318 and Underwater Accelerometer
Type 8319 have a built-in preampli-
fier with a specified lower limiting
frequency (LLF 10% limit) of 0.1Hz
and 0.3Hz respectively.
Most of the standard piezoelectric
accelerometers types are supplied
with an individual frequency re-
sponse curve attached to their cali-
bration chart. Types 4374, 4375, 4393
and all Delta Shear® (without Uni-
Gain®) types are not supplied with
individual curves.
DeltaTron® types are supplied with
individual frequency curves from 10
to 10000Hz as well as typical curves
above and below this range.
Transverse Resonance Frequency
Typical values for the transverse res-
onance frequency are obtained by vi-
brating the accelerometers mounted
on the side of a steel or beryllium
cube using a Calibration Exciter Type
4290.
Phase Response and Damping
The low damping of Brüel&Kjær Ac-
celerometers 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°.
Dynamic Range
The dynamic range defines the range
over which its electrical output is di-
rectly proportional to the acceleration
applied to its base.
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 2Hz to 22kHz) 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
851206/2e
4321 55
4374 0.65†
2.4†
4391 16
8309 3†
8318 470
4371, 4384 11
4378, 4379 175
4382, 4383 17
4370 4381
4375 4393
54 43
Type no. Upper Dynamic Measurement Limit
Weight
grams
Lower Dynamic Measurement Limit
for signal to noise ratio > 6 dB
0.02
0.05 0.1 0.2 0.5 12510 20 50 100200 5001000 mms–2 0.005
0.01 kms–2
0.02 0.05 0.1 0.2 0.5 1.0 2.0 5.0 10 20 50 100 200 500
1000
A
A
A
A
A
A
A
A
L
L
L
L
L
C
C
C
C
C
S
S
S
S
S
L
L
L
L
L
A
A
C
C
S
S
S
S
C
C
C
S
4326 10
ALCS
4394* 2.9
L S
C
4395* 12.9
L
AS
C
4396* 18.2
L
AS
C
4397*
4398*
4399*
2.4
11.8
17.1
A
Fig.7 Equivalent circuit diagrams for accelerometers
760321e
Ca
CcQa
Ca+ Cc
Va=
Cc
Ca
QaRa
Ra
Charge Equivalent Voltage Equivalent
5
Upper Limit
In general, the smaller the acceler-
ometer the higher the vibration level
at which it can be used. The upper
limit depends on the type of vibra-
tion, and is determined by the pre-
stressing 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 han-
dling the maximum shock (±Peak
Transport) and maximum continuous
sinusoidal acceleration (±Peak Tran-
sport) limits for the Type 8318 are
1kms–2 and 0.3kms–2 respectively.
The maximum shock and continu-
ous vibration limits are specified for
vibration in any direction and for fre-
quencies 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 ac-
celerometer. 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 piezoe-
lectric 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. De-
tails concerning the selection of a
suitable preamplifier, together with a
discussion of environmental influenc-
es, can be found in the Brüel&Kjær
“Piezoelectric Accelerometers and Vi-
bration Preamplifiers” handbook.
Electrical Impedance
Fig.7 shows the equivalent circuit di-
agram for accelerometers without
built-in preamplifiers. Since the leak-
age resistance is very high, the accel-
erometers can be regarded as purely
capacitive and the capacitances given
in the Specifications are measured at
160Hz.
Line-drive accelerometers can be
regarded as current sources, the ideal
output impedance for a current
source being infinite. The output im-
pedance 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 imped-
ance of these accelerometers is spec-
ified as a maximum resistance in
Ohms (Ω).
Environmental
Characteristics
Temperature
All Brüel&Kjær accelerometers are
rated for a maximum operating tem-
perature limit. At lower tempera-
tures, the accelerometer piezoelectric
element will exhibit temperature de-
pendent variations in charge and
voltage sensitivity, as well as imped-
ance. Details of these variations are
given on the individual calibration
chart supplied with each accelerome-
ter (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 accelerome-
ters at lower temperatures.
To make measurements on surfaces
with very high temperatures some
form of cooling is needed. Fig.8 illus-
trates a method using a thin conduc-
tive plate and mica washer. For a
250°C (482°F) accelerometer this
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, sur-
face temperatures of up to 450
°
C
(842°F) may be tolerated.
When the insulating stud YP0150
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 max-
imum shock capability.
Temperature Transients
Piezoelectric accelerometers exhibit a
small sensitivity to temperature fluc-
tuations. This effect is significant
when low frequency, low level accel-
erations are being measured.
The temperature transient sensi-
tivity 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 approxi-
mately 30°C. The maximum resulting
output from the accelerometer is re-
corded, and the sensitivity given in
ms–2/°C for a specified LLF. This out-
put 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
RTV738 or similar compounds.
Acoustic Pressure
The acoustic sensitivity of
Brüel&Kjær accelerometers is low
and for most vibration measurement
applications can be neglected. Nor-
mally the acoustically induced vibra-
tion 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 154dB sound pressure level and
measured in the frequency range 2 to
100Hz.
Nuclear Radiation
Except Types with built-in preampli-
fier all Brüel&Kjær accelerometers
Fig.9 Sealing the accelerometer output
connector for operation in humid environ-
ments
Fig.8 Aluminium screen used as a heat
shield allowing the accelerometer to be
operated at high temperatures (for exam-
ple, Type 4370 up to 350°C
6
may be used under gamma radiation
(100Gy/h, 6MeV) up to accumulated
doses of 20kGy (1Gy = 100Rad).
Tests indicate that these accelerome-
ters show less than 10% sensitivity
change after such exposure. Normal
types of accelerometer cable may be
used, but special cables are recom-
mended for accumulated doses ex-
ceeding 1kGy. For greater exposure
levels or for use under heavy neutron
radiation, Industrial Accelerometer
Type 8324 is recommended, and spe-
cial cables are available (see separate
Product Data sheet).
Base Strains
These may be introduced into the ac-
celerometer by distortion of the struc-
ture being measured. To minimise
base strain outputs the DeltaShear®
design is used.
The base strain sensitivity of
Brüel&Kjær accelerometers is meas-
ured by mounting the accelerometer
on a cantilever beam, and producing
a strain of 250µε at the point of at-
tachment. The sensitivity is calculat-
ed 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 ac-
celerometer types. The accelerome-
ters are screwed using a threaded
steel stud onto a clean metal surface
meeting the requirements specified
in Fig.11. Under normal circum-
stances the absolute minimum depth
of 4mm will not be sufficient to ac-
commodate the mounting stud, but is
the minimum depth required to hold
a stud securely. The optimum torque
for tightening 10–32UNF steel studs
is 1.8Nm (15lbin), for M3 steel studs
it is 0.6Nm (5lbin) and for M8 steel
studs it is 4.6Nm (38lbin).
This mounting method is used in
obtaining the specifications of all the
accelerometers with the following ex-
ceptions:
Type 4374 which, due to its small
size, cannot be mounted using a stud.
The recommended mounting tech-
nique, used to obtain the specifica-
tions, utilises a quick setting methyl
cyanoacrylate cement (Brüel&Kjær
no. QS0007). 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 ap-
ply, and the optimum torque is
1.8Nm (15lbin).
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 res-
onance frequency will probably be
lowered.
Fig.12 shows some alternative
mounting techniques. The section en-
Fig.10 Recommended mounting tech-
nique using a steel stud
Fig.11 Recommended tolerances for the mounting surfaces. Dimensions and symbols in
accordance with ISO1101
Fig.12 Alternative mounting techniques
7
titled Standard Accessories lists the
mounting accessories that are sup-
plied with the individual accelerom-
eter types. These mounting
techniques are described in more de-
tail in the Brüel&Kjær “Piezoelectric
Accelerometers and Vibration Pream-
plifiers” handbook, where the effects
of the different methods on the fre-
quency response curve of an acceler-
ometer are illustrated.
Connecting Cables
A number of cables are available for
connection of Brüel&Kjær acceler-
ometers. Refer to page 19 and 20 for
an overview of the various cables and
connector types.
Types 4391, 4391V and 4391E re-
quire TNC connectors. Type 8318,
which also requires a TNC connector,
is supplied with a spiral, TNC to TNC
connector, cable AO0268. Type 8319
is supplied with a 10m integral cable
with a TNC connector. Miniature Ac-
celerometers Types 4374, 4375 and
4375V have integral cables, with a
minimum length of 0.32m, and min-
iature coaxial plugs. Furthermore,
extension connectors and cable
AO0038 are supplied.
Types 4393 and 4393V require sub-
miniature connectors. Type 4393 is
supplied with a subminiature to min-
iature plug coaxial cable AO0283.
All cables include a special noise
reduction treatment and are individ-
ually tested with regard to mechani-
cal and electrical performance. The
max. temperature rating is 260°C
(500°F) except for cable AO0268
which is rated at 85°C (185°F).
DeltaTron® accelerometers are
supplied with a double-screened ca-
ble to reduce the electromagnetic in-
terference to the absolute minimum.
The section entitled Standard Ac-
cessories lists the cables and connec-
tors supplied with each
accelerometer. Additional cable
lengths and connectors can be or-
dered (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 Acceler-
ometer Dimensions.
It is good practice to clamp down
loose cables, as shown in Fig.13, and
this will also help to reduce any pos-
sibility of dynamically induced noise
being generated by the cables.
Preamplifiers and Power
Supplies
With the exception of DeltaTron® ac-
celerometers 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 se-
lection of high performance preampli-
fiers 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
Supply WB1372 or 8 Channel Delta-
Tron® Supply Type 5963. DeltaTron®
Amplifier Type 2646 is a miniature
charge to DeltaTron® amplifier.
Line Drive Accelerometer Type
8318 and Underwater Accelerometer
Type 8319 have a built-in preampli-
fier, but require Preamplifier
EQ2126 and Power Supply EQ2127
due to the line drive principle. Type
8318 can also be supplied as 8318/
WH2146 with charge output.
Using charge preamplifiers, very
long connection cables can be used
without altering the specified sensi-
tivity of the accelerometer and
preamplifier combination.
Fig.13 Clamping the accelerometer cable to minimize cable noise
Fig.14 Brüel&Kjær vibration preamplifiers with charge input
Fig.15 Calibration instrumentation
932238/1e
8
Since ease of calibration and meas-
urement are usually just as impor-
tant as overall gain and frequency
range, most Brüel&Kjær Preamplifi-
ers have one or more of the following
signal conditioning aids:
Sensitivity Conditioning Networks
Allow direct dial-in of transducer sen-
sitivity on the preamplifier, giving
unified system sensitivities.
Integration Networks
Automatically convert measured ac-
celeration to a velocity and/or dis-
placement 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 ac-
celerometer resonance from measure-
ments.
Calibration
Factory Calibration
Brüel&Kjær accelerometers are
thoroughly checked and examined at
all stages of manufacture and assem-
bly. Each accelerometer undergoes an
extensive calibration procedure and
artificial ageing process so as to en-
sure completely predictable perform-
ance 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 Piezo-
electric Accelerometers is by back-to-
back comparison with a primary ref-
erence standard accelerometer cali-
brated at the Danish Primary
Laboratory of Acoustics (DPLA), reg-
ularly checked by the American Na-
tional Institute of Science and
Technology (NIST), the German
Physikalisch–Technische Bundesan-
stalt (PTB) for traceability. The over-
all accuracy of the back-to-back
comparison is 2% with a 99.9% con-
fidence level (1.6% for a 99% confi-
dence level), while for the
interferometry method the accuracy
is better than ±0.6% with a 99% con-
fidence 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
own frequency response, sensitivity
and system calibration, Brüel&Kjær
manufacture the apparatus shown in
Fig.15, for which separate Product
Data sheets are available.
Individual Brüel&Kjær
Accelerometer Types
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 de-
scribed, some of these accelerometers
have been designed for more special-
ized applications, and the special fea-
tures 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 Uni-
Gain® 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. Intrinsi-
cally Safe Accelerometer Type 4391E
is a special version that is certified
intrinsically safe to EExiaI/IICT4,
T5 and T6.
The base of Types 4391/V/E is elec-
trically insulated to prevent ground
loops which might otherwise distort
the vibration signal being measured.
The accelerometers are tested at
500V and typically show that the re-
sistance to ground loop effects is
50MΩ.
Connection to other instruments is
made using a sturdy top mounted
TNC connector. A strong spiral-
wound mini-noise cable A00268 is
available for use with these acceler-
ometers.
DeltaTron® Accelerometers Types
4394, 4395, 4396, 4397, 4398 and 4399
The DeltaTron® accelerometers
(Fig.17) are constructed to the prov-
en Brüel&Kjær DeltaShear design
with the addition of an integral
preamplifier. They require an exter-
nal constant-current power supply
and operate as voltage sources.
DeltaTron® accelerometers operate
over a frequency range from below
1Hz to approximately half the reso-
nance frequency of the accelerometer
assembly. They are available in two
forms, with or without an insulated
base. For further details see the sep-
arate 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 sepa-
rate ThetaShear® accelerometers in
a miniature housing. Its size and
weight make it ideal for use in con-
fined spaces or with delicate struc-
tures. Type 4326 has M3
4391, 4391V &
4391E
Fig.16
4394 4397
4395 4398
4396 4399
Fig.17
4321 & 4321V
Fig.18
9
subminiature connectors made of ti-
tanium.
High Sensitivity Line-drive
Accelerometer Type 8318
Type 8318 (Fig.20) is a very high sen-
sitivity DeltaShear® accelerometer
with a built-in line-drive preamplifi-
er. The Uni-Gain® sensitivity is
316µA/ms–2.
The high sensitivity of this accel-
erometer makes it suitable for meas-
uring very low level vibrations over
a frequency range of 0.1Hz to 1kHz
(10% limit). With a third octave or
narrow band filter included in the
measuring arrangement, measure-
ment of vibration levels down to
0.00002ms–2 is possible. Principal
applications are in vibration investi-
gations 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 EQ2126 and a
Power Supply EQ2127 are required.
8318/WH2146 is a special version of
8318 with charge output.
Connection to measuring instru-
ments is made via a TNC connector,
and a 1.1m long spiral TNC to TNC
cable is supplied with the accelerom-
eter. The spiral cable can stretch to
approx. 4m without being damaged.
For mounting the 8318, 16mm long
M8 threaded steel studs are supplied
with the accelerometer as standard
accessories. Four self-adhesive mount-
ing discs DU0079 are also supplied.
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 trans-
ducers would alter the mode of vibra-
tion, invalidating measurements.
Typical application areas are meas-
urements on thin vibrating panels,
model testing, work in confined spac-
es and measurement of moderately
high level shock.
Type 4374 features a planar shear
construction, weighs 0.65 grams (ex-
cluding cable) and is suitable for
measurement at frequencies up to
26kHz (10% limit). The accelerome-
ter has an integral 32 to 40cm long
connection cable with miniature co-
axial plug attached, and has a plane
base for wax or cement mounting.
Miniature Accelerometers Types
4375, 4375V, 4393 and 4393V
These accelerometers (Fig.22) are
suitable for measurements on light-
weight structures where relatively
high level, high frequency vibrations
are found. The principal application
areas are similar to those of the Type
4374.
Types 4375, 4375V, 4393 and
4393V have a DeltaShear® construc-
tion. Types 4375 and 4393 are Uni-
Gain® types. All types weigh 2.4
grams (excluding cable), and can be
used for measurement of frequencies
up to 16.5kHz (10% limit).
Types 4375 and 4375V have an in-
tegral 32 to 40cm long connection ca-
ble with miniature coaxial plug
attached. Types 4393 and 4393V
have a sub-miniature coaxial socket
for cable connection. All accelerome-
ter types have M3 screw threads for
stud mounting. Types 4375 and
4375V are used for more permanent
vibration monitoring applications on
very light structures in preference to
Types 4393 and 4393V.
Shock Accelerometer Type 8309
Accelerometer Type 8309 (Fig.23) is
especially intended for measurement
of very high level continuous vibra-
tion and mechanical shock up to
150kms–2 and 1000kms–2 peak, re-
spectively.
The 8309 is of a particularly sturdy
construction necessary for withstand-
ing very high level continuous vibra-
tion and shock. Its PZ45 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 40cm long output cable, which
gives the advantage of a reliable out-
put connection at very high shock lev-
els.
For rigid mounting, the base of the
8309 has an integral M5 threaded fix-
ing stud which is adequately dimen-
sioned to transmit the full motion of
the test object to the piezoelectric el-
ement without distortion.
What to Order
Uni-Gain® accelerometers available
from Brüel&Kjær can be supplied in
the form of a Set. An Accelerome-
ter 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 sup-
plied only as an Accelerometer Set.
Fig.24 Accelerometer set
4326
Fig.19
Fig.20
8318
4374
Fig.21
4393 &
4393V
4375 &
4375V
Fig.22
Fig.23
8309
10
* Only for types with no suffix (“V”, “A” and “E” types)
† Only Type 4375
‡ Only Type 4393
Standard Accessories
Brüel& Kjær
Part No. Standard Accessories
4370/1
4381/2/3/4
4370V/1V
4381V/2V/
3V/4V
4321
4321V 4326 4374
4375
4375V
4393
4393V
4391
4391V
4391E
4378
4379 8318 8309
S model includes accessory set (UA xxxx)
in addition to standard accessories (–):
UA 0078 UA0146 UA1079 UA0629 UA0844 UA0856 UA0415
–––––––––
AO0038 260°C (500°F) Teflon® super-low-noise cable,
AC0005 (∅2 mm) fitted with 10–32 UNF
connectors JP 0012. Length 1.2 m (4 ft) 1*3*11
†11
AO0231 260°C (500°F) Teflon® super-low-noise cable,
AC0005 fitted with one 10–32 UNF connector
and one TNC connector. Length 3 m (10 ft) 1
AO0268
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.
1
AO0283 260°C (500°F) Teflon® super-low-noise cable,
AC0205 (∅1.5 mm) fitted with 10–32 UNF
and M3 connectors. Length 1.2 m (4 ft) 3*1‡
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 131
†313
JP 0162 10–32 UNF to TNC connector adaptor 1 3 1 1 1 1
YQ2960 10–32 UNF threaded steel stud. Length 0.5in. 1 4 1 5 1 3 1 5
YP 0150 10–32 UNF insulated stud. Length 0.5 in. 1 1 1
YQ2007 M3 threaded steel stud. Length 8 mm 3*2
YQ2003 M3 threaded steel stud. Length 5 mm 1 3
YQ 9335 M8 steel stud. Length 16 mm 4
DB 0756 Cement stud 10–32 UNF. ∅14 mm 1 1 1
DB 2790 Cement stud 10–32 UNF. ∅25 mm 1
DB 0757 Cement stud M3. ∅8mm 2
UA0642 Mounting magnet & 2 insulating discs DS0553 1 1 1
UA 1077 Small mounting magnet & 2 insulating discs
DS 0786 1
DU0079 1 × adhesive mounting disc. ∅40 mm 4
YO0073 25 × adhesive mounting disc. ∅5.5 mm 1 1
QS0007 Tube of cyanoacrylate adhesive 1 1
YJ0216 Beeswax for mounting 1 1 1 1 1 1 1
YO0534 Insulating mica washer ∅15, ∅5mm 1 1 1*
YO0746 Insulating mica washer ∅25, ∅5mm 5
QA0029 Tap for 10–32 UNF thread 1 1 1 1
QA0041 Tap for M3 thread 1
QA0068 Tap for M5 thread 1
QA0141 Tap for M8 thread 1
QA0013 Hexagonal key for 10–32 UNF studs 1 1 1 1
QA0042 Hexagonal key for M3 studs 1*1
QA0038 Hexagonal key for M4 studs 1
QA0121 Hexagonal key for M8 studs 1
QA0220 Cable connecting/removal tool 1*
YM0334 M3 nut 1
YM0414 10–32 UNF nut 1 1 1
YQ0093 M4 threaded steel screw. Length 16 mm 1 1
YQ8941 M2×10 steel screw 3*
YP 0080
DB 0544 Probe with sharp tip. 10–32 UNF
Round tip 1
Individual calibration chart 1 1 1 1 1 1 1 1 1
Individual frequency response curve 1*1*1*11
11
DeltaTron® Accessories
Brüel& Kjær
Part No. Standard Accessories 4394 4395 4396 4397 4398 4399
S model includes accessory set (UA xxxx)
in addition to standard accessories (–):
UA1218 UA1219 UA1219 UA1218 UA1219 UA1219
––––1––
AO1381 Teflon low-noise cable, double screened AC0104 (∅1.6 mm).
Fitted with 10–32 UNF and M3 connectors. Length 1.2 m (4ft) 11
AO1382 Teflon low-noise cable, double screened AC0104 (∅1.6mm).
Fitted with 10–32 UNF connectors. Length 1.2 m (4 ft) 11 11
JJ0032Extension connector for cables fitted with 10–32UNF connectors 333333
JP014510–32UNF to BNC connector adaptor 111111
YS 8321 Steel stud M3/M3 (UA 1221 is a set of 25 of these studs) 3
YQ2003 Steel Stud M3, 5 mm long 3
YQ2960 10–32 UNF threaded steel stud. Length 0.5in. 2 2 2 2
YQ2962 10–32 UNF threaded steel stud. Length 0.3in. 3 3 3 3
DB 0757 Cement stud M3. ∅8mm 1 1
DB 0756 Cement stud 10–32 UNF. ∅14 mm 1 1 1 1
YG0150 Steel stud 10–32UNF/10–32UNF with flange 1212 1212
UA 0642 Mounting magnet & 2 insulating discs DS 0553 1 1 1 1
YJ0216Beeswax for mounting 111111
YO0073 25 × adhesive mounting disc. ∅5.5 mm 1 1
QS0007 Tube of cyanoacrylate adhesive 1 1
QA0041 Tap for M3 thread 1 1
QA0029 Tap for 10–32 UNF thread 1 1 1 1
QA 0042 Hexagonal key for M3 studs 1 1
QA 0013 Hexagonal key for 10–32 UNF studs 1 1 1 1
YM0414 10–32 UNF nut 1 1 1 1
BC 0200 Individual calibration chart 1 1 1 1 1 1
Individual frequency response curve 1 1 1 1 1 1
Cable Assembly Overview
960335e
AO 0283
Standard
Cable
6)
Front-end
Connector
Extension
Connector Customer Assembled Cable Adaptor
Plug PlugFree-length Cable
Accelerometer
Connector
M3
(Female)
10 – 32 UNF
(Male)
10 – 32 UNF
(Female)
TNC
(Female)
AO 0339
AO 1381
AO 0038
AO 0122
AO 0066
AO 0104
AO 0205
AO 0005
JJ 0207
10 – 32 UNF
2-pin TNC
BNC
TNC
JP 0145
JP 0162
AO 0208
AO 0200
AO 0463
AO 0406
5)
JP 0012
1)
JP 0032
3)
JJ 0032
3)
UA 0641
4)
JP 0056
2)
JP 0056
2)
JP 0012
1)
AO 1419
AO 1382
AO 0231
AO 0231
AO 0193
AO 0268 JJ 0175
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) AO0406 includes JP 0145
6) See also table on last page
12
Additional Accessories Available
JJ0175: Extension connector for
TNC to TNC cable. JJ0207: 2-pin
TNC to 10–32UNF plug adaptor.
JP 0145: 10–32UNF to BNC plug
adaptor. JP0162: 10–32UNF to TNC
plug adaptor. UA0641: 10–32UNF to
BNC extension connector for acceler-
ometers with top connector.
UA 0643: Set of 5 10–32UNF mount-
ing magnets UA0642, ∅24.45mm.
Includes PTFE self adhesive discs
DS0553 for electrical insulation.
UA 1075: Set of 5 UA1077, M3
∅10.2mm. Includes PTFE self adhe-
sive discs DS0786 for electrical insu-
lation.
UA0130: Set of 25 plugs JP0012 for
cable AC0104 and AC0005.
UA0730: Set of 25 plugs JP0056 for
cable AC0200. For mounting the
plugs, the assembly tool QA0035 is
required.
QA0035: Assembly tool for mounting
miniature plugs on accelerometer ca-
bles.
UA 0186: Set of 25 extension connec-
tors JJ0032 for miniature cables with
plugs JP0012 and JP0056.
UA1221: Set of 25 M3/M3 steel studs
YS8321.
UA1192: Set of 10 10–32UNF/
10–32UNF insulating studs UA1215
UA1193: Set of 10 M3/M3 insulating
studs UA1216.
UA 0866: Set of 25 10–32UNF ce-
ment studs DB0756
UA 0867: Set of 25 M3 cement studs
DB0757.
UA0125: Set of 10 insulating studs
YP0150, 10 steel studs YQ2960, 10
nuts YM0414, 10 mica washers
YO0534 plus 10–32UNF tap and
hexagonal key for 10–32 UNF studs.
UA0553: Set of 5 electrically insulat-
ed Mechanical Filters UA0559, plus
a tommy bar for mounting. Also avail-
able with M3 thread as WA0224 (only
1 pc.).
UA 1243: 3×30 red/green/yellow ca-
ble markers for AC0205/AC0104
UA 1244: 3×30 red/green/yellow ca-
ble markers for AC0005/AC0208.
BB0694: Piezoelectric Accelerome-
ters and Vibration Preamplifiers,
Theory and Application Handbook.
13
Accelerometer Dimensions All dimensions in mm
Centre of gravity: “o” seismic mass — “x” whole assembly
Type 4326
Type 4326
Type 4326 has M3 sub-miniature connectors
Types 4321 & 4321V
Types 4391 & 4391V
Types 4375 & 4375V Types 4393 & 4393V
14
Accelerometer Dimensions All dimensions in mm
Centre of gravity: “o” seismic mass — “x” whole assembly
Types 4371 & 4371V Types 4378 & 4378V
841391/1e
Types 4384 & 4384V
841531/2e
Types 4382 & 4382V Types 4383 & 4383V Types 4370 & 4370V
Types 4381 & 4381V
15
DeltaTron® Accelerometer Dimensions All dimensions in mm
Centre of gravity: “o” seismic mass — “x” whole assembly
16
Specifications1
Weight grams 2.410 11 16 17 54 43
Charge Sensitivity for Uni-Gain®-
DeltaShear® types2, 5
pC/ms−20.316 ±2% 1 ±2% 1 ±2% 3.16 ±2% 10 ±2%
pC/g 3.1 ±2% 9.8 ±2% 9.8 ±2% 31 ±2% 98 ±2%
Voltage Sensitivity for Uni-Gain®-
DeltaShear® types5
mV/ms−20.48 0.8 0.8 2.6 8
mV/g 4.8 8 8 26 80
Charge Sensitivity for DeltaShear®
“V” types
pC/ms−20.3 ±15% 1 ±15% 1 ±15% 3 ±15% 10 ±15%
pC/g 3 ±15% 10 ±15% 10 ±15% 31 ±15% 98 ±15%
Voltage Sensitivity for DeltaShear®
“V” types
mV/ms−20.5 0.8 0.8 2.6 8
mV/g 5 8 8 26 80
Mounted Resonance5, 6kHz5542402816
Frequency Range5, 6, 95% Hz 0.2 – 12 000 0.2 – 9100 0.2 – 8700 0.2 – 6100 0.2 – 3500
10% Hz 0.1 – 16 500 0.1 – 12 600 0.1 – 12 00040.1 – 8400 0.1 – 4800
Capacitance5, 7pF 650 1200 1200 1200 1200
Max. Transverse Sensitivity1, 5, 8% <4 <4<4<4 <4
Transverse Resonance kHz 18 15 12 10 4
Piezoelectric Material PZ 23 PZ 23 PZ 23 PZ 23 PZ 23
Construction DeltaShearDeltaShearDeltaShearDeltaShearDeltaShear
Base Strain Sensitivity
(in base plane at 250 µε)
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
Temperature Transient Sensitivity
(3Hz LLF, 20dB/decade)
ms−2/°C 5 0.4 0.2 0.1 0.02 0.04
g/°F 0.28 0.022 0.011 0.0056 0.0011 0.0022
Magnetic Sensitivity
(50 Hz – 0.03T)
ms−2/T30 441 1
g/kGauss 0.3 0.04 0.04 0.01 0.01
Acoustic Sensitivity
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)
ms−20.04 0.01 0.01 0.002 0.001
g 0.004 0.001 0.001 0.0002 0.0001
Min. Leakage Resistance at 20°CGΩ20 20 20 20 20
Ambient Temperature Range °C –74 to 250 –74 to 250 –60 to 180 –74 to 250 –74 to 250
Max. Operational Shock (±Peak) kms−2250 200 20 50 20
g 25000 20000 2000 5000 2000
Max. Operational Continuous
Sinusoidal Acceleration (Peak)
kms−250 60 20 20 20
g 5000 6000 2000 2000 2000
Max. Acceleration (Peak) with
mounting magnet
kms−2– 1.5 1.2 1.2 0.6
g – 150 120 120 60
Base Material Titanium
ASTM Gr. 2
Titanium
ASTM Gr. 2
Titanium
ASTM Gr. 2
Titanium
ASTM Gr. 2
Steel
AISI316
Titanium
ASTM
Gr. 2
1Data obtained in accordance with ANSI S2. 11-69 and ISO/DIS 5347
2Uni-Gain measured sensitivity adjusted to ±2%
3Built-in Line-drive preamplifier. Sensitivity in µA/ms-2
4Local resonances of up to ±1.5 dB permitted
5Individual specifications given on the calibration chart for Uni-Gain types
6Individual curves not supplied with 4375, 4393, 4374, 4321 and 8309 or
DeltaShear“V” types
7With cable supplied as standard accessory, or integral cable
8Axis of minimum transverse sensitivity indicated for Uni-Gain types (except 4321, 4374,
8309)
9The low frequency cut-off is determined by the preamplifier and environmental conditions
4375
4375V 4393
4393V
4384
4384V 4371
4371V
4391
4391V
4382
4382V 4383
4383V
4381
4381V
4370
4370V
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)
17
Specifications1
Weight grams 175 470 0.6510)55 10 310
Charge Sensitivity for Uni-Gain®-
DeltaShear® types2, 5
pC/ms−231.6 ±2% ––1 ±2% – –
pC/g 310 ±2% – – 9.8 ±2% – –
Voltage Sensitivity for Uni-Gain®-
DeltaShear® types5
mV/ms−226 316 ±2%3–0.8 – –
mV/g 260 31003–8 – –
Charge Sensitivity for DeltaShear®
“V” types
pC/ms−2––0.111 ±15% 0.3 0.004
pC/g – – 1.1 9.8 ±15% 3 0.04
Voltage Sensitivity for DeltaShear®
“V” types
mV/ms−2– – 0.18 0.8 – 0.04
mV/g – – 1.8 8 – 0.4
Mounted Resonance5, 6kHz 13 6.5 85 40 X: 40, Y: 30,
Z: 50 kHz 180
Frequency Range5, 6, 9
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
3Hz to
X: 13.3, Y: 10,
Z: 16.6 kHz
1 – 54 000
Capacitance5, 7pF 1200 – 600 1200 1000 100
Max. Transverse Sensitivity1, 5, 8%<4<5<5<4<5<5
Transverse Resonance kHz 3.8 1.6 21 14 X: 18, Y: 18,
Z: 20 kHz 28
Piezoelectric Material PZ 27 PZ 23 PZ 27 PZ 23 PZ 23 PZ 45
Construction DeltaShearDeltaShearPlanar
Shear DeltaShearThetaShearCentreMount.
Compression
Base Strain Sensitivity
(in base plane at 250 µε)
ms−2/µε 0.002 0.0003 0.005 0.02 0.055 2
g/µε 0.0002 0.000 03 0.0005 0.002 0.0055 0.2
Temperature Transient Sensitivity
(3Hz LLF, 20dB/decade)
ms−2/°C 0.001 0.0001 10 0.4 1 400
g/°F 0.000 056 0.000 005 6 0.56 0.022 0.056 22
Magnetic Sensitivity
(50 Hz – 0.03T)
ms−2/T 0.5 1 30 4 12 20
g/
kGauss 0.005 0.01 0.3 0.04 0.12 0.2
Acoustic Sensitivity
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)
ms−20.001 0.001 0.1 0.01 0.035 4
g 0.0001 0.0001 0.01 0.001 – 0.4
Min. Leakage Resistance at 20 °CGΩ20 – 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
Max. Operational Shock (±Peak) kms−250.015
12 250 10 30 1000
g 500 1.512 25 000 1000 3000 100 000
Max. Operational Continuous
Sinusoidal Acceleration (Peak)
kms−250.015
12 50 5 – 150
g 500 1.512 5000 500 – 15 000
Max. Acceleration (Peak) with
mounting magnet
kms−20.2 – – 0.6 – –
g20––60––
Base Material Stainless Steel
AISI316
Stainless Steel
AISI303 Beryllium13 Titanium
ASTM Gr. 2
Aluminium case,
titanium sockets
Stainless
Steel AISI316
10 Excluding cable
11 The transverse resonance frequency may limit the useful frequency range
further
12 Measurement limits. Handling limits given in the Dynamic Range section (pages
4 and 5)
13 Toxic hazard in finely divided form
14 Including Preamplifier EQ2126 and Power Supply EQ 2727
15 4374 Pat. USA 4211951, DK 138768 and GB 1522785. DeltaShear Pat. DK 131401
4378
4379 8318 437415 4321
4321V 4326 8309
18
Specifications
Common to Both Types of DeltaTron® Accelerometer
Type 4394
Type 4397 Type 4395
Type 4398 Type 4396
Type 4399
Sensitivity (axial) at 159.2 Hz, 100 ms−2 (10.2g), 25°C (77°F), 4 mA mV/ms−2
(g) 1.00
(9.807) ±2%10.0
(98.07) ±2%
Measuring Range (peak) temperature <100°C (212°F) ms−2 (g) ±7500 (765) ±750 (76)
temperature <125°C (257°F) ms−2 (g) ±5000 (510) ±500 (51)
Frequency Range (±10%) Hz 1 to 25000 0.3 to 18000 1 to 14000
Maximum Transverse Response % <4
Constant Current Supply temperature <100°C (212°F) mA +2 to +20
temperature <125°C (257°F) mA +2 to +10 +2 to +20
Supply Voltage, unloaded for full specification V DC +24 to +30
minimum (reduced specification) V DC +18
Output Impedance W <100
Bias Voltage at 25°C (77°F), 4 mA V 12 ±0.5
full temperature and current range V 8 to 15
Residual Noise from 1 to 22000 Hz µV<25 <15 <40
equivalent acceleration ms−2 (g) <0.025 (0.0026) <0.015 (0.0015) <0.004 (0.0004)
Polarity (acceleration directed from base into body) Positive
Recovery time from Overload (2 ×maximum level) µs<20 <15 <25
Maximum Non-destructive
Shock (peak)
Axial ms−2 (g) 100000 (10200) 50000 (5100) 20000 (2040)
Transverse ms−2 (g) 50000 (5100) 20000 (2040) 10000 (1020)
Temperature Range °C (°F) −50 to +125 (−58 to +257)
Humidity Welded, sealed
Temperature Transient Sensitivity ms−2/°C20.20.1
g/°F0.11 0.011 0.0056
Magnetic Sensitivity (50 Hz, 0.038T) ms−2(g)/ T 10 (1) 20 (2) 5 (0.5)
Acoustic Sensitivity (154dB SPL) ms−2 (g) 0.01 (0.001) 0.005 (0.0005) 0.002 (0.0002)
Construction DeltaShear
Piezoelectric Material PZ 23
Case Material Titanium ASTM Gr. 2
Connector Coaxial M3 miniature 10–32UNF
Mounting Thread Tapped center-hole M3 10–32 UNF
Mounting Torque Nm (lb.in) 0.2 to 0.6
(1.8 to 5.3) 0.5 to 3.5 (4.4 to 31)
19
Specifications
DeltaTron® — Insulated Base
Mounted Resonance Frequency kHz523728
Transverse Resonance Frequency kHz 15 13 9
Case Insulation to Ground MΩ>10
Base Strain Sensitivity ms−2(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)
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
AC0005 AC0066 AC0104 AC0200 AC0205 AC0208
Temperature (°C) –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
Screen Single Single Double Double Single Single
Capacitance (pF/m) 106 95 105 95 100 100
Dimension (mm) Ø2.0 Ø1.0 Ø1.6 Ø3.2 Ø1.5 Ø2.0
10– 32 plug for self-mounting JP 0012 JP 0012 JP 0012 JP 0056 JP 0012 JP 0012
4394 4395 4396
4397 4398 4399
Brüel & Kjær
BP 0196
–
20
97/01
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
Brüel&Kjær reserves the right to change specifications and accessories without notice
Specifications for
Reference and
Underwater
Accelerometers
Weight grams 40 44
(with 0.15 m cable)
Charge Sensitivity for DeltaShear®
“V” types
pC/ms−20.124–
pC/g 1.24–
Current Sensitivity2 Uni-Gain®
Line Drive types
µA/ms−2–1 ±2%3, 4
µA/g – 9.8 ±2%3, 4
Mounted Resonance kHz 30 (with 20 g load)4>35
Frequency Range7Hz 0.2 – 3100 (1%)4
0.2 – 4400 (2%)40.3 – 11 000 (10%)
Capacitance5pF 180 –
Max. Transverse Sensitivity % <24, 6<4
Transverse Resonance kHz – 14
Piezoelectric Material Quartz PZ 23
Construction Inverted Centre
Mounted Comp. DeltaShear
Base Strain Sensitivity1
(in base plane at 250 µε)
ms−2/µε Top: 0.01
Base: 0.003 0.01
g/µε Top: 0.001
Base: 0.0003 0.001
Temperature Transient Sensitivity1
(3Hz LLF, 20dB/decade)
ms−2/°C0.5 1
g/°F 0.028 0.056
Magnetic Sensitivity1
(50 Hz – 0.03T)
ms−2/T 1 7
g/kGauss 0.01 0.07
Acoustic Sensitivity1
Equiv. Acc. at 154 dB SPL
(2 – 100 Hz)
ms−20.008 0.01
g 0.0008 0.001
Min. Leakage Resistance at 20°CGΩ1000
(10 at 200°C) –
Ambient Temperature Range °C –74 to +200 –50 to +100
Max. Operational Shock (±Peak)1kms−210 20 (axial)
g 1000 2000 (axial)
Max. Operational Continuous
Sinusoidal Acceleration (Peak)
kms−210 –
g1000 –
Max. Acceleration (Peak) with
mounting magnet
kms−21–
g100 –
Base Material Stainless Steel
AISI316
Stainless
UHB 904L
1 Data obtained in accordance with ANSI S2. 11-69 and ISO/DIS 5347
2 Uni-Gain measured sensitivity adjusted to ±2%
3 Built-in Line-drive preamplifier
4 Individual specifications given on the calibration chart
5 With integral cable supplied as standard
6 Axis of minimum transverse sensitivity indicated
7 The low frequency cut-off is determined by the preamplifier and environmental conditions
8305
83192
* Includes 10–32 UNF/BNC Adaptor JP 0415
Cables with and without connectors
Free-lengthCable Connector
Type Order No.
Type Length
(m)
AC 0005
310–32 UNF/TNC AO 0231
1.2 TNC/TNC AO 0193
1.2 10– 32 UNF/10–32 UNF AO 0038
3 10–32 UNF/10–32 UNF AO 038F
5 10–32 UNF/10–32 UNF AO 0038G
10 10–32 UNF/10–32 UNF AO 0038H
30 10–32 UNF/10–32 UNF AO 0038K
x 10–32 UNF/10–32 UNF AO 0038V-
AC 0005-x
30 AC 0005K
50 AC 0005L
100 AC 0005M
200 AC 0005N
AC 0200
3 10–32 UNF/10–32 UNF AO 0122
5 10–32 UNF/10–32 UNF AO 0122G
10 10–32 UNF/10–32 UNF AO 0122H
30 10–32 UNF/10–32 UNF AO 0122K
x 10–32 UNF/10–32 UNF AO 0122V-
AC 0200-x
30 AC 0200K
100 AC 0200M
200 AC 0200N
AC 0104
1.2 M3/10– 32 UNF AO 1381
1.2 10– 32 UNF/10–32 UNF AO 1382
3 10–32 UNF/10–32 UNF AO 1382F
5 10–32 UNF/10–32 UNF AO 1382G
5 10–32 UNF/10–32 UNF*AO 0406
10 10–32 UNF/10–32 UNF AO 1382H
30 10–32 UNF/10–32 UNF AO 1382K
x 10–32 UNF/10–32 UNF AO 1382V-
AC 0104-x
30 AC 0104K
100 AC 0104M
AC 0208
1.2 10– 32 UNF/10–32 UNF AO 0463
3 10–32 UNF/10–32 UNF AO 0463F
5 10–32 UNF/10–32 UNF AO 0463G
10 10–32 UNF/10–32 UNF AO 0463H
30 10–32 UNF/10–32 UNF AO 0463K
x 10–32 UNF/10–32 UNF AO 0463V-
AC 0208-x
200 AC 0208N
AC 0205
1.2 M3/10– 32 UNF AO 0283
3 M3/10–32 UNF AO 0283F
5 M3/10–32 UNF AO 0283G
10 M3/10–32 UNF AO 0283H
30 M3/10–32 UNF AO 0283K
x M3/10–32 UNF AO 0283V-
AC 0205-x
30 AC 0205K
100 AC 0205M
AC 0066
1.2 10– 32 UNF/10–32 UNF AO 1419
1.2 M3/10– 32 UNF AO 0339
x M3/10–32 UNF AO 0339V-
AC 0066-x
30 AO 0066K
Spiral 1.1 – 4 TNC –TNC AO 0268

Navigation menu