BG 800 300 BE / A (0105) TPG 300
39
6.2.2 Operating and calibration problems
Problem
Possible cause
Correction
No display appears when the unit is
switched on
Unit switched off for too short a period
of time
After switching the unit off, wait approx. 10 sec-
onds before restarting
Pressure display unstable
Filter time constant too low
Increase the filtering (
→
section 4.7.7)
Switching functions (relays) flutter
Hysteresis too small
Modify the threshold values (
→
section 4.7.4)
Increase the filtering (
→
section 4.7.7)
Pirani pressure display too high
Pirani gauge contaminated
Calibrate the measuring circuit
Clean the gauge (
→
&
[4] ... [6])
Replace the gauge
Pirani measurement circuit cannot be cali-
brated
Combination measurement plug-in
board / gauge cable / gauge is not
compatible
Select correct combination (
→
&
[3])
Pirani gauge severely contaminated
Clean the gauge (
→
&
[4] ... [6])
Replace the gauge
Cold cathode pressure display too high
Contaminated or moist connector in-
sulation
Clean or replace connector
Humidity (
Þ
leak current)
Keep humidity low, keep the unit switched on
Cold cathode pressure display too low
Cold cathode gauge contaminated
Clean the gauge (
→
&
[7] ... [10])
«no P» is displayed
No plug-in board has been installed
Install the appropriate plug-in board
2)
Incomprehensible display
Plug-in board not screwed down
Tighten the screws
Contacts contaminated / bent
Clean / carefully straighten contacts
2)