Drawing Number: 21106
Revision: NR
OPERATION MANUAL FOR
MINIATURE ICP
PRESSURE SENSOR
105A AND 105C SERIES
3
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).
PASSAGE
LENGTH (in.)
PASSAGE
RESONANCE
(kHz)
APPROX.
FASTEST
PULSE RISE
TIME (u Sec)
.050
66
5
.100
33
10
.200
16.5
20
.50
6.6
50
1.0
3.3
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 propagation of sound caused by
changes in temperature and pressure of the medium in
the passage.
For best matching of passage to diaphragm, maintain
the .010
”
clearance ahead of the diaphragm as shown
in Typical Recessed Installation figure.
4.0 OPERATION
Connect sensor to signal conditioner as shown below,
depending upon sensor style being used.
Model 480A
Signal Conditioner
To Readout
070A09 Solder
Connector Adaptor
105A
Solder Terminal
2-Wire Cable
Scope
XDCR
Typical Circuit Connection (For 105A)
Typical Circuit Connection (For 105C02,C03,
C12, C13, C22, C23, C33, C43)
NOTE: All PCB signal conditioners for ICP
sensor
contain current-limiting circuitry to set the input
current in the range of 2 to 20 mA.
Do not connect a power supply to these units without
current limiting. To do so will destroy the built-in IC
amplifier.
All PCB signal conditioners feature fault-monitoring
voltmeters on the front panel. During normal
operation, the meter will indicate about mid-scale
(+11 volts). If one of the connections to the sensor is
open, the meter will read full scale (yellow area).
Should a short occur on the sensor line, the meter will
read 0 volts (red area).
5.0
CALIBRATION
Because of the relatively short discharge time
constant of this series, static calibration means cannot
be used. Fast dynamic means such as step function or
pulse generators must be used instead.
Contact the factory for help in solving specific
calibration problems.
6.0
MAINTENANCE
The small size and sealed construction of these
sensors precludes field maintenance and repair.
Should a problem develop, contact the factory for
assistance.
002A Cable
XDCR Scope
To Readout
Model 480A
Signal
Conditioner
XDCR
