Drawing Number: 21113
Revision: NR
OPERATION MANUAL FOR
ICP
HIGH PRESSURE SENSORS
Models 109A, A02, A11, A12
Models 109B11, B12
1
1.0 INTRODUCTION
The Model 109A is an acceleration-compensated high
pressure sensor designed to measure very fast
transient pressure pulses as produced by detonations,
gas guns, projectiles and closed bomb tests. These
types of tests are usually accompanied by very large
acceleration pulses which can add considerable error
to output signals of noncompensated sensors.
The Model 109A features a very high natural
frequency, minimizing ringing effects usually
triggered by very short rise time input pulses.
The Model 109A02 is similar in all respects to the
Model 109A except for range. The 109A has a range
of 80,000 psi, while the 109A02 is rated at 100,000
psi full scale.
The 109A series is not intended for continuous duty
such as in fuel injector pumps.
2.0
DESCRIPTION
The Model 109A (see figure below) contains a very
rigid
acceleration-compensated
quartz
element
coupled to a tiny microelectronic amplifier located
near the electrical connector.
Series 109A Sensor
This amplifier (actually an impedance converter with
unity gain) converts the high-impedance level voltage
from the quartz package into a low-impedance (100
ohms), high-level (6 V-109A, 7 V -109A02) output
signal. The amplifier utilizes two wires, i.e. signal
and power are conducted through a single coaxial
connector.
The signal is separated from the bias level (about +11
V) in the power unit by use of a decoupling capacitor
when using power units Series 480B, 482A, 483A,
485B and others.
The signal is separated from the bias level by DC
voltage level-shifting methods in power unit
Model 484B. This unit is useful for calibration.
See Guide G-0001B, "General Guide to ICP
Instrumentation", for more complete coverage of
ICP
(Integrated Circuit Piezoelectric) instruments.
3.0
INSTALLATION
The series 109A Sensors mount directly in existing
ports machined for PCB Models 118A, 108A and
119A.
Unlike conventional diaphragm type sensors, the
109A is pressure sensitive over the entire frontal area.
For this reason, extra care should be exercised to
avoid bottoming in mounting hole when recessed
mounted and especially when mounting into existing
mounting ports.
A torque wrench should be used to monitor the
mounting torque value when installing the series
109A. The recommended range is given on the
installation drawing.
3.1
MOUNTING
IN
EXISTING
RECESSED PORTS
Before installing the sensor in previously used
mounting ports, clean out residue from previous tests
as shown in figure below. This can be accomplished
by hand reaming the 1/4" diameter hole using a PCB
Model 040A end cutting reamer (or equivalent).
10-32 Co-Axial
Connector
ICP Amplifier
5/16 Hex
3/8-24 Thd.
Ceramic Coating
Acceleration
Compensated Element
