MKS HPS 903 Series, Operation And Maintenance Manual

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18
Cold Cathode Ionization Vacuum Sensor
Maintaining the Series 903 (IMT)
Troubleshooting and Service
The Series 903 (IMT) is designed to be maintenance-free under normal
operation. If a problem should occur, the following chart lists symptoms,
possible causes, and their remedies. With this guide, you should be able to
diagnose some problems and correct them. Those which fall outside the
scope of this chart or problems related to the electronics assembly are
generally not serviceable by the user, and the (IMT) should be returned to
HPS
TM Products for repair.
1. Inspect and clean if necessary.
Refer to page 19.
1. Connect D-sub.
2. Turn power on.
3. Return to HPS
TM for repair.
1. Connect pin 9 to pin 4. Refer to
page 9, Input/Output Wiring.
1. Wait for discharge to start or increase
pressure to speed up starting time.
Consider purchasing an IgniTorr™.
2. Beyond range. Increase pressure if
desired.
1. Check cable connection.
2. Turn power on.
1. Increase supply voltage to provide 14 to
30 V at the (IMT).
1. Check set point.
2. Check any external switches which
may be controlling this line.
3. Return to HPS
TM
for repair.
Troubleshooting Chart
Pressure readings are too
erratic.
No analog output voltage.
Analog output voltage
higher than 9.5 V.
Analog output voltage less
than 1.5 V.
Analog output voltage less
than 0.5 V and LED off.
Analog output voltage less
than 0.5 V and LED on.
Set point relay will not
operate.
1. Contaminated sensor.
1. D-sub is disconnected.
2. Power supply turned off.
3. Defective PC board.
1. High voltage is turned off.
1. Discharge has not started.
2. Pressure is less than 3 x 10 -10
Torr
1. No supply voltage.
2. Power supply turned off.
1. Supply voltage too low.
1. Set point voltage incorrectly
set.
2. Pin 7 of D-sub connected to
ground at power supply.
3. Defective PC Board.
Symptom Possible Cause Remedy