TROUBLESHOOTING
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Symptom: The indicator does not exceed 2 kPa when atmospheric pressure is measured.
• The type of the sensor head or
sensor head cable length differs
from the specified one.
(1) Change it with a specified one.
(2) Adjust or recalibrate with the one currently in use.
• Gas under measurement is not
nitrogen.
(1) The type of gas used for calibration of this gas is nitrogen.
• The sensor head is contaminated or
its filament has worn out.
(1) Replace the sensor head.
• The sensor head or controller is
installed in a place where tempera-
ture is high. (This gauge was
calibrated at about 25°C.)
(1) Move the gauge to a clean, well ventilated place not blown
with draft.
Symptom: The needle vibrates and does not indicate a fixed value.
• The type of the sensor head or sensor head
cable length differs from the specified one.
(1) Change it with a specified one.
(2) Adjust or recalibrate with the one currently in use.
• The sensor head is contaminated or its
filament has worn out.
(1) Replace the sensor head.
• Leak in the sensor head or a leak in the
place where the sensor head is installed.
(1) If there is a leak in the sensor head, replace it.
(2) If the leak is elsewhere, stop it.
• Increased wire resistance due to poor
contact of the sensor head cable or
corrosion of the wire rod.
(1) Check the sensor head cable referring to Fig. 18.
(2) Replace the sensor head cable.
• The line voltage is not within 100 to 240
VAC.
(1) Hold the line voltage within 100 to 240 VAC.
Symptom: Meter relay contact output is not actuated.
• The needle is not yet lower than the
pressure of the relay setting needle.
(1) The relay contact output is not actuated until the
pressure lowers below the relay setting needle.
• The relay circuit power is not supplied.
(1) Check the rear of the meter, referring to Fig. 12
Turn OFF power.
Before touching any terminal on the rear of the meter or if there is a possibility
of touching it, turn OFF the vacuum gauge power and the power applied to the
setpoint output terminal. Contact with the terminal, to which the voltage (24
VDC) is applied, will cause electric shock if power is turned ON.
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