OPERATION MANUAL FOR
ENGINE COMBUSTION SENSORS
Modes 112B10 & 112B11
Model 175A01
1
1.0 INTRODUCTION
Self-generating piezoelectric sensors, because of
their extreme rigidity and wide dynamic range, excel
in the measurement of repetitive and transient
phenomena. In most applications, the instruments do
not significantly alter the process or structure being
tested. Also, they measure accurately over any
partial or incremental portion of their full-scale
range. But they cannot measure static inputs or
absolute levels over extended time periods because of
excessive drift when operating electrostatically.
Piezoelectric sensors generate an electrical voltage in
response to pressure, force, or vibratory motion at
high impedance levels. This voltage is conditioned
by means of an isolation amplifier for display on a
readout instrument.
Series 112B10: Engine Combustion Sensors
Series 175A: Engine Combustion Sensor
2.0 INSTALLATION
Carefully install the sensor according to instructions
detailed on the enclosed installation drawing.
3.0 OPERATION
Using low-noise cable, connect the charge mode
sensor to the charge or source-follower amplifier
with short or medium decay time constants. The
input or feedback circuits in these amplifiers
eliminate DC signal components causing the output
signal to decay exponentially following static or step
function inputs. This action distorts transient
measurements if the event lasts longer than a small
percent of the decay time constant. The action also
shifts to zero the average level or repetitive signals
with DC components similar to an oscilloscope
operating in an AC mode.
Switch power on and proceed with measurements.
Manual Number: 21069
Manual Revision: A
ECR Number: 22421