Model 167A11
Ballistics shot shell pressure sensor, 15k psi, floating clamp nut design
Installation and Operating Manual
For assistance with the operation of this product,
contact PCB Piezotronics, Inc.
Toll-free: 800-828-8840
24-hour SensorLine: 716-684-0001
Fax: 716-684-0987
E-mail: info@pcb.com
Web: www.pcb.com
Warranty, Service, Repair, and
Return Policies and Instructions
The information contained in this document supersedes all similar information that
may be found elsewhere in this manual.
Total Customer Satisfaction – PCB
Piezotronics guarantees Total Customer
Satisfaction. If, at any time, for any
reason, you are not completely satisfied
with any PCB product, PCB will repair,
replace, or exchange it at no charge. You
may also choose to have your purchase
price refunded in lieu of the repair,
replacement, or exchange of the product.
Service – Due to the sophisticated nature
of the sensors and associated
instrumentation provided by PCB
Piezotronics, user servicing or repair is
not recommended and, if attempted, may
void the factory warranty. Routine
maintenance, such as the cleaning of
electrical connectors, housings, and
mounting surfaces with solutions and
techniques that will not harm the
physical material of construction, is
acceptable. Caution should be observed
to insure that liquids are not permitted to
migrate into devices that are not
hermetically sealed. Such devices should
only be wiped with a dampened cloth
and never submerged or have liquids
poured upon them.
Repair – In the event that equipment
becomes damaged or ceases to operate,
arrangements should be made to return
the equipment to PCB Piezotronics for
repair. User servicing or repair is not
recommended and, if attempted, may
void the factory warranty.
Calibration – Routine calibration of
sensors and associated instrumentation is
recommended as this helps build
confidence in measurement accuracy and
acquired data. Equipment calibration
cycles are typically established by the
users own quality regimen. When in
doubt about a calibration cycle, a good
“rule of thumb” is to recalibrate on an
annual basis. It is also good practice to
recalibrate after exposure to any severe
temperature extreme, shock, load, or
other environmental influence, or prior
to any critical test.
PCB Piezotronics maintains an ISO9001 certified metrology laboratory and
offers calibration services, which are
accredited by A2LA to ISO/IEC 17025,
with full traceablility to N.I.S.T. In
addition to the normally supplied
calibration, special testing is also
available, such as: sensitivity at elevated
or cryogenic temperatures, phase
response, extended high or low
frequency response, extended range, leak
testing, hydrostatic pressure testing, and
others. For information on standard
recalibration services or special testing,
contact your local PCB Piezotronics
distributor, sales representative, or
factory customer service representative.
Returning Equipment – Following
these procedures will insure that your
returned materials are handled in the
most expedient manner. Before returning
any equipment to PCB Piezotronics,
contact your local distributor, sales
representative, or factory customer
service representative to obtain a Return
Materials
Authorization
(RMA)
Number. This RMA number should be
clearly marked on the outside of all
package(s) and on the packing list(s)
accompanying the shipment. A detailed
account of the nature of the problem(s)
being experienced with the equipment
should also be included inside the
package(s) containing any returned
materials.
PCB for a complete statement of our
warranty. Expendable items, such as
batteries and mounting hardware, are not
covered by warranty. Mechanical
damage to equipment due to improper
use is not covered by warranty.
Electronic circuitry failure caused by the
introduction of unregulated or improper
excitation power or electrostatic
discharge is not covered by warranty.
A Purchase Order, included with the
returned materials, will expedite the
turn-around of serviced equipment. It is
recommended to include authorization
on the Purchase Order for PCB to
proceed with any repairs, as long as they
do not exceed 50% of the replacement
cost of the returned item(s). PCB will
provide a price quotation or replacement
recommendation for any item whose
repair costs would exceed 50% of
replacement cost, or any item that is not
economically feasible to repair. For
routine calibration services, the Purchase
Order should include authorization to
proceed and return at current pricing,
which can be obtained from a factory
customer service representative.
Contact Information – International
customers should direct all inquiries to
their local distributor or sales office. A
complete list of distributors and offices
can be found at www.pcb.com.
Customers within the United States may
contact their local sales representative or
a
factory
customer
service
representative. A complete list of sales
representatives can be found at
www.pcb.com. Toll-free telephone
numbers for a factory customer service
representative,
in
the
division
responsible for this product, can be
found on the title page at the front of this
manual. Our ship to address and general
contact numbers are:
Warranty – All equipment and repair
services provided by PCB Piezotronics,
Inc. are covered by a limited warranty
against
defective
material
and
workmanship for a period of one year
from date of original purchase. Contact
DOCUMENT NUMBER: 21354
DOCUMENT REVISION: B
ECN: 17900
PCB Piezotronics, Inc.
3425 Walden Ave.
Depew, NY 14043 USA
Toll-free: (800) 828-8840
24-hour SensorLineSM: (716) 684-0001
Website: www.pcb.com
E-mail: info@pcb.com
OPERATION MANUAL FOR
Series 167
BALLISTICS PRESSURE SENSOR
1.0
INTRODUCTION
Series 167 are charge mode, general purpose
ballistics sensors with a welded diaphragm and a
rugged quartz element package. The sensors’ welded
diaphragms provide better transient thermal
characteristics that are important for ballistic
applications. Series 167 is approved by SAAMI for
against-the-case (undrilled) shotshell production
testing of plastic-cased ammunition.
Chamber
pressure is sensed by the sensor as the round is fired.
In addition to ballistics testing, the 167 Series can be
used for hydraulic and pneumatic test applications.
2.0
DESCRIPTION
Figure 1 below shows the internal construction and
external configuration of the 167 Series.
3.0
1
INSTALLATION
The 167 Series mounts directly in existing ports
machined for PCB Models 118A, 119A, 108A, 109A
and others. See above figure.
A torque wrench should be used to determine the
mounting torque value when installing the sensor.
The recommended range is given on the installation
drawing.
It is wise to replace the seal each time the sensor is
reinstalled.
3.1
MOUNTING
IN
RECESSED PORTS
EXISTING
Before installing the sensor in previously used
mounting ports, clean out residue from previous tests
as shown in figure 2.
Model 040A Reamer
10-32 MICRO
CONNECTOR
5/ 16 HEX
3/ 8-24 THREAD
Residue
QUARTZ CRYSTALS
WELDED DIAPHRAGM
Figure 1
The 3/8-24 thread and flush diaphragm design are
conventional, providing direct interchangeability with
existing machined diaphragm type piezoelectric
sensors.
The short, rigid element and stiff diaphragm give the
167 Series a 250,000 Hz natural frequency and good
linearity even below 1000 psi.
Drawing Number 21104
Revision: NR
Figure 2
This can be accomplished by hand reaming the 1/4"
diameter hole using a PCB Model 040A end-cutting
reamer (or equivalent).
Should waveform distortion occur during prolonged
testing, remove residue as shown. If the seal surface
requires machining to clean it after prolonged use, do
not forge to deepen the 1/4” diameter hole by the
same amount. Otherwise, the sensor may bottom
when installed.
OPERATION MANUAL FOR
Series 167
BALLISTICS PRESSURE SENSOR
3.2
PREPARING NEW MOUNTING
PORTS
Refer to installation drawing provided in this manual
for instructions in mounting hole preparation. For
best results, do not deviate from the steps outlined in
this drawing.
Use good machining practice in preparing the
mounting port, paying particular attention to the seal
surface (.323 diameter), and keeping it free from tool
chatter marks.
Note:
3.3
It is important that this surface be perfectly
smooth and free from nicks or other
discontinuities which might cause leaks at
high pressures.
The passage behaves like an underdamped second
order system, the resonant frequency being
determined by the passage length. This can have a
limiting effect on pressure pulse rise time while
causing passage ringing in cases where the passage is
too long.
The following relationship determines this resonant
frequency (fr):
fr 
v
4L
Hz
(EQ. 1)
Where: fr = Resonant frequency of passage (Hz)
v = Velocity of sound in air (ft/sec)
RECESSED MOUNT
The recessed installation is shown in figure 3. This
type of mounting protects the sensor diaphragm from
the effects of high-flash temperatures and particle
impingement due to blast effects, thereby prolonging
sensor life.
2
L = Length of column (ft)
For air at room temperature, (EQ.1) becomes:
fr 
3300
L
(EQ. 2)
Where: L = Passage length (in.)
The natural frequency and approximate fastest
pressure step rise time for various length passages is
shown in the following chart (Medium, air at 25C):
.010
min.
Figure 3
The recommended range of passage diameters is .090
to .125 diameter.
The limitation in this type of installation lies in the
frequency-limiting effects of the passage, due to its
length.
Drawing Number 21104
Revision: NR
PASSAGE
LENGTH
(in.)
.050
.100
.200
.50
1.0
PASSAGE
RESONANCE
(kHz)
66
33
16.5
6.6
3.3
APPROX.
FASTEST RISE
TIME (uSec)
5
10
20
50
100
Passage Resonance vs. Passage Length
Actual resonant frequencies measured in practice may
differ slightly from the chart values due to variations
in the velocity of sound in air caused by changes in
temperature and pressure of the air in the passage.
OPERATION MANUAL FOR
Series 167
BALLISTICS PRESSURE SENSOR
If possible, keep passage lengths below .10 inches for
best results in most ballistic applications, especially at
casemouth and when measuring port pressures.
For best matching of passage to diaphragm, maintain
the .010 clearance ahead of the diaphragm as shown
in previous figure.
3.4
FLUSH MOUNT
In the flush mount installation, there is no reduced
area passage from the sensor diaphragm to the test
chamber; rather, the sensor diaphragm is mounted
flush with (or slightly recessed from) the inside
surface of the test chamber.
Use this type of installation only if space or rise time
considerations preclude the use of the recessed
installation.
In severe pyrotechnic environments, sensor life may
be severely limited with flush installation.
For flush mount installations, a silicone rubber
coating approximately .010” thick can be effective.
General Electric RTV type 106 silicon rubber is
recommended. It is best to recess the diaphragm
.010” for this type of protection.
3.6
Use only low-noise treated coaxial cable (PCB Model
003A or equivalent) to connect sensor to the charge
amplifier, in-line voltage amplifier, or other high
input impedance readout instrument. Protect the
ultra-high impedance connection against moisture
contamination with shrink tubing or other suitable
means. The two following figures illustrate typical
circuit connections.
It is good practice to support sensor cables by tying
them to rigid structures to prevent excessive motion
which can generate noise and materially shorten cable
life. Allow adequate strain relief loop.
4.0
3.5
FLASH TEMPERATURE
EFFECTS
Although the 167 Series has better thermal
characteristics than the 118B due to its welded
diaphragm, additional precautions may be taken, if
required, against flash temperature effects.
Some of these measures can include filling the
recessed passage with silicone grease (DC-4 or
equivalent).
The application of several layers of black vinyl
electrical tape directly on the diaphragm has proven
effective in many cases.
Flash temperature effects are usually longer term and
will show up as baseline shift, long after the event to
be measured has passed.
INSTALLING CABLES
CALIBRATION
These sensors can be calibrated using static hydraulic
techniques such as by dead weight testers or, by
comparison, with a static pressure sensor coupled
with a readout device.
Use charge amplifier on "long time constant" and
allow sensor to thermally stabilize before attempting
to calibrate.
Note: Do not attempt to use a charge amplifier which
has less than a 5000 second time constant
in the "long TC" position.
Several charge amplifiers are designed especially for
use with ceramic accelerometers for higher frequency
measurements. In general, these types are not
suitable for calibration of quartz pressure sensors by
quasi-static means.
A factory charge calibration is supplied with each
sensor. Factory recalibration is available at a nominal
charge.
Drawing Number 21104
Revision: NR
3
OPERATION MANUAL FOR
Series 167
BALLISTICS PRESSURE SENSOR
5.0
4
OPERATION
Model 003A05 Cable Model 167A
In-Line Charge
Amplifier
Most test set-ups will include the sensor working into
an electrostatic charge amplifier such as the PCB
Model 462A.
ICP Power Unit
Note: Keep the input cable to the charge amplifier as
short as practical as electrical noise at the output
of any charge amplifier is directly related to input
cable length (capacitance).
Depress ground button of charge amplifier and adjust
electrical zero if necessary.
Readout
Model 070A02 Adaptor
Model 012A03 Cable
Range the amplifier as desired to give the necessary
full-scale voltage.
Figure 5: Typical Circuit Connection with In-Line
Voltage or Charge Amplifier
For normal, drift-free operation, switch charge
amplifier time constant selector to "medium" or
"short" during use.
6.0
5.1
POLARITY
Since most charge amplifiers are inverting amplifiers,
the 167 Series is designed to produce a negativegoing charge for increasing pressure at the
diaphragm.
Special positive output versions are available for use
with non-inverting ICP source follower amplifiers.
(Models 401A and 402A.) Specify P167 Series to
order the positive polarity model.
Model 167A
Cable Model 003A05
Model 070A02 Adaptor Readout
Charge Amplifier
Model 012A03 Cable
Figure 4: Typical Circuit Connection with
Laboratory- Type Charge Amplifier
Drawing Number 21104
Revision: NR
MAINTENANCE
The only maintenance required on the 167 Series is
the cleaning of the connector to restore insulation
resistance.
At times during use in damp environments or after
period of storage, the insulation resistance of these
sensors may degrade (1012 ohms is normal).
To restore insulation, wipe connector end with clean
cloth or paper towel dipped in trichlor alcohol or
equivalent solvent and bake sensor in 250 F oven for
several hours. A vacuum oven, if available, will
hasten the process.
7.0
INSTALLATION FOR USE IN
SHOTSHELL TESTING
When the 167 Series is to be used for ballistics
testing of shotshell ammunition, the sensor must be
positioned such that the diaphragm is as close to
perfectly flush with the chamber I.D. as possible (See
figure 6).
Prepare the mounting port as shown in Installation
Drawing No. 167-1010-91 or 1751. The approved
SAAMI location is 1.000 inches forward of the
boltface, intersecting the C/L of the barrel.
OPERATION MANUAL FOR
Series 167
BALLISTICS PRESSURE SENSOR
5
As shown in figure 7, it is essential that the
diaphragm surface and the inner diameter of the
chamber be perfectly tangent. To facilitate this
adjustment, a set of spacer washers (Model 065A19)
of various thickness is supplied with each model of
the 167 Series to be used for this application.
By trial and error, it is a simple matter to select the
proper thickness spacer for each installation.
Note: Frequent removal and reinstallation may result
in a permanent "squeezing" deformation of
the spacer washer, especially if excessive
torque is used during the installation. This
deformation may allow the sensor diaphragm
to enter the chamber too deeply.
It is important that the sensor not be overtorqued. If
possible, always measure this mounting torque so as
to prolong sensor and seal life, as well as to maintain
accuracy of calibration.
TANGENT
Figure 7: Shotshell Ammunition
The proper mounting torque is specified on the
installation drawing.
1.000
Drilled Cartridge
Location
Cartridge
Test Barrel
Figure 6
ICP is a registered trademark of PCB Piezotronics
Drawing Number 21104
Revision: NR