PCB Piezotronics ICP W138A25 User manual

Model W138A25/-0003
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 traceability to SI through
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
Warranty, Service, Repair, and
Return Policies and Instructions

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, NY14043 USA
Toll-free: [phone]
24-hour SensorLineSM: [phone]
Website: www.pcb.com
E-mail: [email protected]

PCB工业监视和测量设备 - 中国RoHS2公布表
PCB Industrial Monitoring and Measuring Equipment - China RoHS 2 Disclosure Table
部件名称
有害物质
铅(Pb)
汞
(Hg)
镉
(Cd)
六价铬(Cr(VI))
多溴联苯 (PBB)
多溴二苯醚(PBDE)
住房
O
O
O
O
O
O
PCB板
X
O
O
O
O
O
电气连接器
O
O
O
O
O
O
压电晶体
X
O
O
O
O
O
环氧
O
O
O
O
O
O
铁氟龙
O
O
O
O
O
O
电子
O
O
O
O
O
O
厚膜基板
O
O
X
O
O
O
电线
O
O
O
O
O
O
电缆
X
O
O
O
O
O
塑料
O
O
O
O
O
O
焊接
X
O
O
O
O
O
铜合金/黄铜
X
O
O
O
O
O
本表格依据 SJ/T 11364 的规定编制。
O：表示该有害物质在该部件所有均质材料中的含量均在 GB/T 26572 规定的限量要求以下。
X：表示该有害物质至少在该部件的某一均质材料中的含量超出 GB/T 26572 规定的限量要求。
铅是欧洲RoHS指令2011/65/ EU附件三和附件四目前由于允许的豁免。
CHINA RoHS COMPLIANCE

DOCUMENT NUMBER: 21354
DOCUMENT REVISION: C
ECN: 45605
Component Name
Hazardous Substances
Lead
(Pb)
Mercury
(Hg)
Cadmium
(Cd)
Chromium VI
Compounds
(Cr(VI))
Polybrominated
Biphenyls
(PBB)
Polybrominated
Diphenyl
Ethers (PBDE)
Housing
O
O
O
O
O
O
PCB Board
X
O
O
O
O
O
Electrical
Connectors
O
O
O
O
O
O
Piezoelectric
Crystals
X
O
O
O
O
O
Epoxy
O
O
O
O
O
O
Teflon
O
O
O
O
O
O
Electronics
O
O
O
O
O
O
Thick Film
Substrate
O
O
X
O
O
O
Wires
O
O
O
O
O
O
Cables
X
O
O
O
O
O
Plastic
O
O
O
O
O
O
Solder
X
O
O
O
O
O
Copper Alloy/Brass
X
O
O
O
O
O
This table is prepared in accordance with the provisions of SJ/T 11364.
O: Indicates that said hazardous substance contained in all of the homogeneous materials for this part is below the limit
requirement of GB/T 26572.
X: Indicates that said hazardous substance contained in at least one of the homogeneous materials for this part is above
the limit requirement of GB/T 26572.
Lead is present due to allowed exemption in Annex III or Annex IV of the European RoHS Directive 2011/65/EU.

Drawing Number: 21102
Revision: NR
OPERATION MANUAL FOR
Series 138
1
Series 138 Standard Length, with Lead Wire Hole for Attaching Weights
Series 138 Short Length, One-Piece Molded Closed-End Tube
1.0 INTRODUCTION
PCB Series 138 are voltage mode tourmaline sensors
designed for operation underwater or in liquids
compatible with tygon and nylon. (See specification
sheet in the back of the manual for range and
sensitivity).
Series 138 feature built-in ICP®amplifiers which
convert the high-impedance voltage from the crystals
into a low-impedance output voltage of less than 100
ohms. Power to operate the IC amplifier and the
output signal are conducted over a single conductor
coaxial cable with a shield serving as signal return.
Special low-noise cables are not required.
Series 138 are used by the military for underwater
explosive testing, commercial use in gasoline tanks
and transformer shock wave applications. The
sensors are ideal for monitoring dynamic pressures
because they exhibit near non-resonant response.
The charge generated by deflection of the
piezoelectric element when subjected to shock waves
creates a voltage on the input capacitance at the gate
of the amplifier. The amplifier, in conjunction with
the source element, transforms this input into a low-
impedance signal of equal amplitude. The DC bias
that exists on the signal lead is blocked from the
output by a coupling capacitor in the PCB signal
conditioners.

Drawing Number: 21102
Revision: NR
OPERATION MANUAL FOR
Series 138
2
Some models of the Series 138 feature a tygon tube
closed at one end with conical-shaped delrin plug.
The plug features a small hole for attachment of a
weight. Other models feature a one-piece molded
closed tube.
2.0 INSTALLATION, CABLE
ATTACHMENT, AND SEALING
THE CABLE/CONNECTOR
ASSEMBLY
Various methods are used to mount the 138 sensors
for use in liquids. Care should be taken to prevent
conductive liquids from entering the cable or
connector assemblies, where they could cause
corrosion, short circuiting or degradation of
insulation resistance.
For low-pressure (<500psi) dynamic measurements, a
standard low-noise coaxial cable with an extruded
teflon jacket and a 10-32 connector can be used.
Heat shrink tubing, RTV silicon rubber or sometimes
silicone grease can make an adequate seal in an
environment with low static pressure.
For high static pressures due to deep submersion or
use in a pressure vessel, alternate methods of sealing
the cable/connector may be required. A method of
waterproofing the cable/connector assembly of a 138
which also provides protection to the cable is to put a
flexible tube (plastic, tygon, etc.) around the cable
and cable/connector assembly. Tie the tube at the
metal housing with monofilament or fine steel wire.
The opposite end of the tube must be above the level
of the liquid or sealed around the cable to prevent
liquid from entering the protective tubing. Filling the
protective tube with a non-conducting liquid such as
Dow Coming silicone oil can be done to prevent the
tube from collapsing. This will also equalize pressure
inside and outside the tubing, helping to prevent a
conductive liquid (such as water) from entering.
In some blast applications, when using a standard 10-
32 micro cable/connector, the high shock can flex the
cable/connector joint enough to move the center pin
of the 10-32 cable connector. This can cause noise
on the output signal. Protecting the connection from
shock may be required.
PCB Model 070A03 adaptor can be used to adapt the
10-32 micro jack on the 138 to a BNC jack. A
heavier coaxial cable (eg. RG-58/U) can now be used
in place of the micro cable. Because of the large
mass of the 070A03 compared to the 10-32 jack, this
connection should be sealed and protected from
shock and turbulence. Putting a two to three inch
diameter of duct seal, wrapped with a waterproof
tape, will seal the connection and provide shock
protection at the cable/connector/ amplifier assembly.
PCB Model 070A09 Solder Connector Adaptor can
also be used to attach a short length (~two to three
inches) of ribbon cable to a 138. The ribbon cable
can then be soldered to an extension cable. The
ribbon cable and both solder connections should be
sealed with a suitable waterproofing material.
Various types of sealing materials such as
polyethylene and flexane have been shown to be
effective for sealing cables, connectors, etc.
2.1 MOUNTING OR SUSPENDING
THE SENSOR
After the cable/connector assembly is sealed, the
sensor can be suspended in the liquid where the
measurement is to take place. For low dynamic
pressure measurements (less than 500 psi), models
featuring a small hole in the conical end piece of the
tube allow attachment of a light weight (~two lb.) to
suspend the sensor in a vertical position.
The line should be of light material (monofilament,
15 lb. test) to enable it to break easily. This way, the
sensor does not pull apart in the turbulence caused by
the collapse of gas bubbles resulting from a shock
wave.
For higher pressure dynamic measurements, alternate
methods of suspending the sensor should be used to
minimize damage from turbulence. Taping or
attaching (with cable ties) the sensor amplifier
housing to a braided steel wire is a method that is
suited for use in higher dynamic pressure
measurements.

Drawing Number: 21102
Revision: NR
OPERATION MANUAL FOR
Series 138
3
The steel wire can have a weight attached to it to
submerge the entire assembly. Tape or attach the
coaxial cable loosely to the steel wire at ~one foot
intervals. Attach a monofilament line (~50 lb. test) to
the end of a steel wire braid, and let it hang down past
the end of the sensor.
Attach a three to five lb. weight to the end of the
monofilament and tape the sensor to the
monofilament.
Another method of mounting the sensor is to tape the
sensor to the surface of a structure. (The pressure
measured when mounted to the surface of a structure
will be twice the free field pressure since the pressure
wave reflected off the surface adds to the pressure
wave initially striking the sensor.)
For applications in which the 138 is immersed only a
few feet into a liquid, and the blast may be in very
close proximity to the sensor, a steel pipe can be
placed around the cable and sensor so that only the
tourmaline sensing element is exposed to the blast.
Since the static pressure is not high, a standard micro
cable with 10-32 coax connector can be used with
heat shrink tubing to seal the cable/connector.
3.0 OPERATION
It is necessary only to supply the sensor with a 2 to 20
mA constant current at +20 to +30 VDC through a
current-regulating diode or equivalent circuit. See
Guide G-0001B for powering and signal utilization
information pertaining to all ICP®instrumentation.
Most PCB signal conditioners have an adjustable
current feature allowing a choice of input currents
from 2 to 20 mA.
In general, for best resolution, choose the lower
current ranges, and for driving long cables (to several
thousand feet) use the higher current, up to 20 mA
maximum. Line-impedance matching may be
necessary to produce flat-frequency response over
long (hundreds or thousands of feet) cables.
Switch power on and observe reading of bias
monitoring voltmeter on front panel of the signal
conditioner.
If indicator is in green section of indicator panel, the
IC amplifier is producing proper bias (+8 to 14
VDC), cable connections are normal and the system
is ready to operate.
If the needle moves to the red area of the fault
monitor meter, output is zero and a short is indicated.
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.
Allow the sensor to stabilize for about one minute. A
signal drift may occur when 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.
4.0 CALIBRATION
Series 138 are calibrated dynamically using a drop
weight tester. For best accuracy, use the calibration
certificate supplied. Factory recalibration is available
for a nominal charge.
5.0 POLARITY
This sensor series produces a positive-going output
voltage for increasing pressure input. See the
specification sheet for polarity of the sensor.
6.0 LOW-FREQUENCY RESPONSE
The low-frequency response of an ICP®system is
determined by:
l.) The discharge time constant of the sensors.
2.) If AC-coupled at the power unit, the
coupling time constant.
Consult Section 7 in General Guide G-0001B for a
detailed explanation of low-frequency characteristics
of ICP®instruments.

Drawing Number: 21102
Revision: NR
OPERATION MANUAL FOR
Series 138
4
7.0 MAINTENANCE
Observe the following precautions when using the
sensor:
l.) Keep connections clean and dry.
2.) Do not exceed specified maximum range.
3.) Do not subject sensor to temperatures
exceeding 100 °F.
4.) Do not apply voltage to sensor without
current-limiting diodes or other current protection.
5.) Do not apply more than 20 mA of current to
the sensor.
®ICP is a registered trademark of PCB Piezotronics,
Inc.