OPERATION MANUAL FOR
MODELS 122A, 122A21, 122A22, and 122A244
HELIUM BLEED PRESSURE SENSOR
6.0GROUND ISOLATION
All sensor probes in this series are mounted in an "OFF GROUND" configuration. That is, the probe body is electrically insulated from the sensor outer body to avoid ground loops.
7.0MAINTENANCE AND REPAIR
The sealed construction and miniature size of these sensors make field repair impractical.
The helium filter element should be cleaned should the flow rate decrease. Remove the element and ultrasonically agitate in solvent for 15 minutes, then dry.
Should the orifice become plugged, back pressure the orifice by applying air pressure to diaphragm end of sensor with filter off and helium tube vented to atmosphere.
The only maintenance possible on the probe is maintaining of insulation resistance of the Model 122A probe/cable assembly. Clean connectors with suitable solvent and dry.
Contact factory for assistance should problems arise.
®ICP is a registered trademark of PCB Piezotronics
Drawing number: 21089
Revision: NR
