tina56e1-f (2015-09)
61
Troubleshooting sensor (Pirani filament)
If the cause of a fault is suspected to be in the sensor, the
following checks can be made with an ohmmeter.
Separate the sensor from the electronics unit (
→
62).
Using an ohmmeter, make the following measurements on the
contact pins.
Ω
Sensor
Possible cause
PCG550 (W)
PCG554 (W)
40 ± 1 [
Ω
]
>>40
Ω
Contamination
<<40
Ω
Contamination
∞
Filament broken
PCG552 (Ni)
35 ± 1 [
Ω
]
>>35
Ω
Contamination
<<35
Ω
Contamination
∞
Filament broken
Correction
All of the above faults can only be remedied by replacing the
sensor (
→
62).