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Diatron MI PLC
rev 1.09
50
5.1.2. Normal range of Self Test parameters
Parameter
Unit
Lower bound
Upper bound
HGB light
count
3000
60000
HGB dark
Count
0
3000
Electrode voltage
V
45
55
Current
µA
830
930
Offset
mV
-5.0
5.0
Amplifier test
count
19990
20005
Peak of test pulses
mV
1500
1800
deviation (noise)
mV
0
80
Noise test
pls/5sec
0
5
Outer pressure
mBar
500
1050
Vacuum
mBar
125
420
Drift
mBar/10sec
0
10
Power +12V
V
11.0
12.5
Power
–12V
V
-13.0
-11.0
Power Batt.
V
1.8
4.5
Core Temp.
°C
-
-
5.1.3. Troubleshooting Guide for Self test
Parameter
Mark
Possible reason
Remedy
HGB dark
HIGH
Instrument door open
Close instrument door
HGB light
LOW
HGB head not connected or
HGB LED out of order
Check HGB head connections
check HGB LED during
measurement
HIGH
Instrument door open or
HGB LED too bright
Close door or replace HGB
LED resistor on amplifier board
Electrode voltage
LOW
or
HIGH
Fault on High Voltage
or Amplifier board
Check measuring voltage (50V) on
High voltage and Amplifier boards
Current
LOW
or
HIGH
Fault on Amplifier board
Check current generator, and test
generator FET on Amplifier board
Offset
LOW
or
HIGH
Fault on Amplifier board
Check the offset potentiometer on
Amplifier board
Amplifier test
LOW
Amplifier Boards is not
connected to main board
Check cables and connectors
coming from the Amplifier
HIGH
Instrument not grounded
Check mains ground lead
Peak of pulses
LOW
or
HIGH
Fault on Amplifier board
Check current generator, and test
generator FET on Amplifier board
Dev. (noise)
HIGH
Instrument not grounded
Check mains ground lead
Noise
HIGH
Instrument not grounded
Check mains ground lead
Outer pressure
LOW
or
HIGH
Pressure sensor, cable or
connector problem
Check pressure sensor, cable
connections and controller board
pressure connector
Vacuum
LOW
Peristaltic pump failure
Check peristaltic pump
Drift
HIGH
Leakage in pneumatics
Check tubing in pneumatics