AVL AVL DiCom 4000, Service Manual

Page: 88 / 182

Evaluation Unit AVL 4000
4-56 Service Manual
Field 2 Raw data for the measuring instrument unit
CO
CO
2
HC
NO
19 bit ADC values
These values are recorded during calibration at the works (see "Service" printout in the
Appendix to the Operating Manual).
•
Enter the values in the maintenance manual at every service.
−
If any value falls below 50 % of the original value, this suggests that the measuring
cell is contaminated replace the measuring cell (see section 5.2.3 Measuring
Cell).
−
After replacing the measuring cell, always carry out a gas calibration (see
Operating Manual).
−
After replacing the measuring cell, also record the raw data (in the maintenance
manual) and enclose a new "Service" printout.
O2
This value is recorded during calibration at the works (see "Service" printout in the
Appendix to the Operating Manual).
•
Enter the value in the maintenance manual at every service. Check the drop in voltage
from one service to the next.
•
If the O
2
sensor looks likely to show a voltage of less than 5 mV by the next routine
service, the O
2
sensor needs replacing (see Operating Manual).
P
T
Raw values for pressure and temperature
Field 3
Description of channels
•
If all values are 00, the measuring instrument unit is functioning properly.
•
If all values are not 00, switch the tester off and on again at the main power switch up
to three times. If after this, the values have not reset to 00, the measuring instrument
unit needs replacing (see section 4.3 Dismantling the 4-/5-Gas Measuring Instrument
Unit).
•
Exception: 5-gas measuring instrument (under SCCS)
The 02 value indicates that the sensor must be replaced in the near future.