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8.
TROUBLESHOOTING
Symptom:
No display appears on the front panel when power is turned ON.
Possible cause
Corrective action
• The power cord is disconnected.
1) Check the power cord for connection.
• The line voltage is below the specified
range.
1) Check the line voltage by a circuit tester.
Check line voltage.
Prior to turning ON the power, make sure that the vacuum gauge operating
voltage and the supply voltage are in agreement. Connection of incorrect
power can cause damage to the vacuum gauge and fire.
Symptom:
The display is blinking at 2.7
×
10
+3
Pa and does not change when pressure has lowered.
Possible cause
Corrective action
• Pressure is still higher than the
measurement range.
(atmospheric pressure, for example)
1) Normal
Symptom:
The display remains blinking at E.E
×
10
E
.
Possible cause
Corrective action
• The sensor head filament has burnt out.
1) Check the filament for continuity referring to Fig.
13-5 "Sensor head filament connection diagram".
The filament resistance value is about 13 ohms
under atmospheric pressure. Replace the sensor
head if the filament has burnt out.
Do not energize the filament with a current of 10
mA or more. Its life will be shortened.
• The sensor head filament is
disconnected or in poor contact.
1) Check the sensor head cable referring to Fig. 13-6
"Sensor head cable connection diagram".
• The sensor head, measuring unit and
sensor head cable are not connected to
the controller.
1) Securely connect the sensor head, measuring unit
and sensor head cable.
Symptom:
The display remains at 0.0
×
10
-1
Pa and does not change though the pressure has
increased.
Possible cause
Corrective action
• Pressure is still below the measurement
range.
1) Normal
