Checking The "Analysis" Function - Bosch ETT 008.31 Repair Instructions

5.5

Checking the "Analysis" function

In analysis mode, the device automatically performs a system adjustment every 15 minutes. However, if analysis is taking place at that
moment, the next system adjustment is only initiated once analysis has ended, i.e. as soon as the probe is withdrawn from the exhaust
pipe and the measured values have dropped to zero. Pressing the pump button triggers purging with ambient air and terminates the
analysis. A new analysis may be started at any time before the pump comes to a stop (run-on time 15sec.)
Sequence
Press pump button.
Automatic system adjustment takes place.
Display:
Gas measuring channels
Engien speed and oil temperature
Upper-range values of gas-measuring channels.
Display during analysis:
CO cntent less than 2%: Display of
2
*)Or Err Err if oil temperature sensor is not yet connected. Err Err Err
Terminate analysis by pressing the pump button. The pump runs on for approx. 15sec., in order to purge the gas ducts with ambient
air via the zero-gas inlet. Analysis may be re-started while the pump is still running.
Checking the stability of the display
Monitor the stability of the displayed values of the gas-measuring channels for approx. 2 minutes.
When the oil-temperature sensor is connected, the oil-temperature display indicates the measured temperature; minor adaptation
variations are insignificant. In the case of noticeable fluctuations, however, perform trouble-shooting to Section 8.11.
Error limits for fluctuations (noise) in gas-measuring channel displays:
CO display 0 %Vol.
CO display 0 %Vol.
2
O display 20.9 %Vol.
2
HC display 0 ppm + 20 ppm
The HC display must stabilize at a value of < 20 ppm after approx. 2 minutes.
= 0.0
= Current values
Current measured values
oil temperature *).
+ 0.005 % vol.
+ 0.2 %vol.
+ 0.4 %vol.
Time Display
15 sec.
0
0.0
0
9990
15 sec.
20.9
0
1030
19.8
0
0.000
0.0
25
10.00
18.0
25
1.25
1.03
25
23