PCB Piezotronics 137B23B User manual

Model 137B23B
ICP® Pressure Sensor
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: [phone]
E-mail: [email protected]
Web: www.pcb.com

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 ISO-
9001 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
Warranty, Service, Repair, and
Return Policies and Instructions

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.
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.
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
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.
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:
PCB Piezotronics, Inc.
3425 Walden Ave.
Depew, NY 14043 USA
Toll-free: [phone]
24-hour SensorLineSM: [phone]
Website: www.pcb.com
E-mail: [email protected]
DOCUMENT NUMBER: 21354
DOCUMENT REVISION: B
ECN: 17900

Drawing Number: 40955
Revision: NR
ECO#: 39372
OPERATION MANUAL FOR
FREE FIELD BLAST PRESSURE PROBE
Models 137B21X, B22X, B23X, B24X
1
1.0 INTRODUCTION
The Series 137B2XX Free Field Blast ICP
®
Pressure
Probe is designed for measuring free field blast and
shock tunnel pressure time profiles.
Designed with an ICP
®
built-in source follower
amplifier, the 137B2XX Series offers sensitivities of
1, 20, 10 and 100 mV/psi with full-scale ranges from
0 to 50, 250, 500 or 5000 psi. The 137B2XX Series
is constructed with a stable quartz piezoelectric
element in an Invar housing
2.0 INSTALLATION
In field blast measurements, mount the Series
137B2XX pressure probe in an axial direction to the
blast source. The probes should be elevated high
enough off of the ground such that ground does not
interfere with the measured pressure. See photo 1.
Photo 1
The sensing surface should be aligned in a vertical
plane with respect to the ground as shown in photo 2.
Avoiding direct exposure of the diaphragm to
sunlight is good practice so that changing
temperatures throughout a test day do not change the
sensitivity of the sensor. In any case care must be
taken such that the sensor’s diaphragm is not oriented
down to avoid ground reflections.
In some cases, where flash temperatures such as those
generated by blasts and shock fronts are present, it
may be necessary to thermally insulate the diaphragm
to minimize signals generated by these effects.
Photo 2
Common black vinyl electrical tape has been found to
be an effective thermal insulating material in many
cases. One layer may be used across the end of
diaphragm and adaptor. See photo 3.
Photo 3
A silicone rubber coating approximately 0.010 inch
(0.25 mm) thick has also been proven effective in
many applications. General Electric RTV type 106 is
recommended (PCB Model 065A67). Apply the
rubber coating to the surface of the diaphragm and
allow it to cure in accordance with the manufacturer’s
instructions.
3.0 OPERATION
Using suitable cable, connect the sensor to one of
PCB's Series 480, 481, 482, 483, or 484 signal
conditioners or equivalent power supply. If using a
PCB line power unit, the equipment will supply the
137B2XX with an adjustable 2 to 20 mA constant
current at +22 to +30 VDC through a current-
regulating circuit. If using a battery-operated unit,
the constant current is 2 mA. See Guide G-0001 for
powering and signal utilization information pertinent
to all ICP
®
instrumentation.

Drawing Number: 40955
Revision: NR
ECO#: 39372
OPERATION MANUAL FOR
FREE FIELD BLAST PRESSURE PROBE
Models 137B21X, B22X, B23X, B24X
2
Switch power on and observe reading of bias
monitoring voltmeter on front panel of signal
conditioner.
If indicator is in green section of indicator panel, the
IC amplifier is producing proper bias (8 to 14 VDC),
the cable connections are normal, and the system is
ready to operate.
If the pointer moves into the red area of the fault
monitor meter, output is zero and a short is indicated.
The short could be located in amplifier cable
connectors or power unit.
If the pointer moves into the yellow area of the fault
monitor meter, an open circuit is indicated with full
power supply voltage.
An open circuit could be the result of a faulty
amplifier, an open cable or open connectors. Check
to be sure connectors are properly mated. Some PCB
power units feature fault LEDs in place of a fault
meter. Instead of a pointer, the fault LED will light
when an open or short circuit condition is present.
Allow the sensor to thermally stabilize for about one
minute. A signal drift may occur when the cable is
connected to the readout instrument. This drift
occurs during charging of the coupling capacitor in
the power unit. The signal will stabilize in several
minutes. Proceed with measurements.
Most line-powered signal conditioners manufactured
by PCB have an adjustable current feature allowing a
choice of input currents from 2 to 20 mA. In general,
for the lowest noise (best resolution), choose the
lower current ranges.
In order to maintain a high frequency response of the
system when driving long cables (to hundreds or
thousands of feet), use a higher current, up to 20 mA
maximum. Use of low-capacitance cable (i.e. RG
62/U) and impedance-matching variable resistors are
suggested to improve long cable performance
characteristics. See Guide G-0001 for a discussion
on cable considerations.
3.1 POLARITY
The 137B2XX Series produces a positive-going
output voltage for increasing pressure output.
4.0 LOW-FREQUENCY RESPONSE
Consult Section 7.0 in General Guide G-0001 for
detailed explanation of low-frequency characteristics
of ICP
®
instrumentation.
5.0 CALIBRATION
Do not try to calibrate the Series 137B2XX statically.
The Series 137B2XX is calibrated dynamically by
PCB using a hydraulic pulse technique.
For best accuracy, use the calibration certificate
supplied. Factory recalibration is available for a
nominal charge.
6.0 MAINTENANCE
Although ICP
®
sensors have low-output impedance
and are not usually affected by moisture, in extremely
damp environments it may be well to protect cable
connections with shrink tubing.
It is well to observe the following precautions in
using the sensor:
1. Do not exceed specified maximum range.
2. Do not subject sensor to temperatures
exceeding temperature shown on specification sheet.
3. Do not apply voltage to sensor without
current-limiting diodes or other current protection.
4. Do not apply more than 20 mA of current to
the sensor.
Field repair of the piezoelectric element or amplifier
of the Series 137B2XX is not practicable. Thus,
should a sensor in this series require servicing, refer
to the warranty sheet.
CAUTIONARY NOTE: If sensors are left outside
overnight, they should be coated with silicone oil and
covered. The protective silicone oil or grease coating
should also be applied when the sensors are operated
in a humid or rainy environment.
®ICP is a registered trademark of PCB Piezotronics