AVL DiGas 4000 - Page 115

4000 4-/5-Gas Measuring Instruments Unit
Service Manual 5-19
Primary error symptom Primary cause
(of error)
Secondary cause of
error
Possible tests/
establishing cause
Remedy
Measurement
values fluctuate
significantly
See “Measurement values fluctuating
significantly” or “Zeroing not possible”
Pressure or temperature measurement
value not OK
See related pressure measurement values,
temperature measurement values
Ambient air heavily polluted with
petrol, exhaust gas…
Can you smell
anything?
Air the room
Wrong calibration
values input
Check calibration
values and gas
values, propane/
hexane ok?
Carry out power
reset; then
CALIBRATION
Calibrated several
times with slightly
incorrect values
Internal ref.
comparison shows
that deviations are
too large
Check calibration
values and gas
values, propane/
hexane ok?
Carry out power
reset; then
CALIBRATION
Instrument not in
30 minute
calibration mode
Error in warm-up
phase or significant
fluctuations in
ambient
temperature
Check zero status in
service mode (must
be 1E), DSM must
be 00
Place instrument
somewhere else
Wait another 15 min
Calibration not
possible
Calibration error Check status of
CO2CS, COCS and
HCCS
Eliminate error,
carry out power
reset, then
CALIBRATION
Capacitor burnt
out or faulty
Power supply unit
or EMC?
Smell of burning Replace faulty part
Check power supply
unit
Replace measuring
instruments unit
Detector
preamplifier faulty
Chopper is switched
off (by software)
Check error status
ES
Replace faulty part
Check power supply
unit
Replace measuring
instruments unit
CHOPPER failed
Chopper motor is
catching
Andros software
error
Clicking sound can
be heard
Replace measuring
instruments unit