Requirements For Exhaust Analysis; Preparation Of Exhaust Analysis; Sequence Of Measurement; Recalibration With Test Gas - Bosch ETT 008.71 Instructions D'emploi

4. Exhaust analysis
4.1 The following must be tested before exhaust
analysis commences
- the sampling sensor (for damage and blockages);
- the coarse filter GF1 (for presence and damage);
- the sampling hose (for damage and blockages);
- filters GF2, GF3 and GF4
- outlet hoses (PVC, 3 connected)
4.2

Requirements for exhaust analysis

- The engine must be warm (oil temperature > 60 °C).
- No aids to starting (automatic or manual) must be operating.
- The exhaust pipe must not leak.
- The engine must have the ignition settings specified by the
manufacturer (dwell angle, ignition timing and idling speed).
4.3

Preparation of exhaust analysis

Danger: exhaust fumes are poisonous!
Exhaust fumes must be extracted from confined spaces.
With exhaust systems with one silencer, but two tail pi-
pes, both tailpipes must be fed into a common collector
pipe.
- Switch off the engine and ignition.
- Push the sampling sensor (9) into the exhaust tailpipe or the
common collector pipe as far as possible. Fasten the sampling
sensor to the tailpipe or collector pipe using the clip provided.
- When taking samples between the engine and the catalytic
converter, the full length of the sampling hose (8 m) must be
used between the vehicle and the analyser. Observe the
temperature limit for Viton hose (max. 200 °C).
The filter (7) must also be used.
4.4

Sequence of measurement

The sequence followed during the measurement is specified by
the respective test system connected.
4.5

Recalibration with test gas

Particularly high long-term stability is a feature of the analyser. Ne-
vertheless, legal requirements may entail its recalibration at regular
intervals. Service agencies set the requisite parameters.
The test system displays a warning message before the re-ad-
justment interval is due to expire. You must then re-adjust the
instrument before this interval expires using test gas, as described
in Section 5.1.
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4.6 Maintenance
Regular maintenance will ensure that the unit will continue to
operate reliably and accurately. If the maintenance interval is not
kept to, the test system displays a warning message informing you
that it is time to carry out maintenance work.
The maintenance work carried out must be confirmed under the
test functions of the respective test system. For a detailed descrip-
tion of maintenance work, see Section 7.