Ulvac GI-M2 - Page 78

72
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Pressure cannot be measured with the filament turned ON.(The [FIL] lamp
on the panel is lit.)
Possible cause
Corrective action
Insulation between the electrodes
of the sensor head has failed.
Check insulation between the electrodes of the sensor
head and between the electrodes and the outside wall
using a Megger. (The Megger indication should be
infinite.)
(See page 86)
If insulation failure is verified, replace the sensor
head.
The sensor head cable is
disconnected or insulation has
failed.
Check insulation between electrodes of the sensor
head using a Megger. Also check the connector at
both ends for continuity using a circuit tester.
(See page 89～.)
Note:
After checking the ion collector (coaxial contact)
for insulation using a Megger, short the points
measured by the Megger to discharge the
charge. If it is reconnected without
discharging, the DC amplifier of the controller
may be damaged.
Replace or repair the sensor head cable.
Sensor head sensitivity has
lowered noticeably.
Change the sensor head with another one and check
the symptom. If OK with another sensor head, the
sensor head is faulty.
Replace the sensor head.
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The filament is turned OFF immediately after it is turned ON or the filament
cannot be turned ON.
Possible cause
Corrective action
Filament protection is activated
because of high pressure.
Check pressure using another type of vacuum
gauge, e.g. Pirani gauge.
EXT-PROTECT is activated.
If the [PROT] lamp on the front panel is lit, external
protection input is activated.
Reset the PROTECT signal.
Turn off the FIL ON signal and then turn it ON
again.
Remote operation status is set up
from RS-232C.
If the [REMOTE] lamp on the front panel is lit,
remote operation status is set up.
At this time,
operation from the front panel
and external I/O
connector are not feasible.
Turn on the filament through RS-232C.
Reset [REMOTE] and select front panel operation.
Remote operation status is set up
by external I/O connector.
If the [REMOTE] lamp on the front panel is lit,
remote operation status is set up.
At this time,
operation from the front panel is not feasible.
Turn on the filament form the external I/O connector.
Reset [REMOTE] and select front panel operation.