Preventive Maintenance; 20 7.4.1 Leak-Tightness Of Sampling System; 20 7.4.2 Exhaust Gas Sampling Probe; 20 7.4.3 Exhaust Gas Sampling Hose - Bosch BEA 750 Manual Original

7.4

Preventive maintenance

i
If they have to be opened (repair work), units
are then to be re-calibrated (see also bulletin
on calibration of exhaust gas analyzers for spark
ignition engines). Unit repairs (opening, adjustment,
servicing etc.) can only be performed by authorized
Service personnel.
GF 3
O2 AF I
7 6 5
4
459906_4Rf.eps
11
10
Fig. 7: BEA 750
1 Coarse filter GF2
2 Coarse filter GF3
3 8 m hose assembly
4 Active carbon filter AF1
5 O sensor
2
6 Measurement gas outlet
7 Gas and condensate outlet (transparent PVC hose)
8 Coarse filter GF1
9 30 cm Viton hose (black)
10 Exhaust gas sampling probe
11 Plastic hose for leak test
7.4.1 Leak-tightness of sampling system
To ensure accurate exhaust emissions tests, it is
essential that there are no leaks in the sampling system
(exhaust gas sampling probe, hoses, coarse filters). It is
therefore advisable to conduct the leak test daily.
7.4.2 Exhaust gas sampling probe
Keep the opening at the tip of the exhaust gas
sampling probe clean. In the event of HC residue and
condensate, detach the exhaust gas sampling probe
from the hose and blow compressed air through it in
the opposite direction to the intake flow.
7.4.3 Exhaust gas sampling hose
Check for damage. In the event of HC residue or
condensate, detach the hose from the measuring device
and blow compressed air through it in the opposite
direction to the intake flow.
Robert Bosch GmbH
GF 2
1
2
3
8
9
Maintenance | BEA 750 | 29
7.4.4

Coarse filter

i
When replacing the coarse filters GF1, GF2 and
GF3 always use original filters with the order no.
1 687 432 005.
If other filters are used (e. g. commercially available fuel
filters), the downstream measurement chambers will be
damaged by corrosion residue (e.g. rust particles from
metal filter elements) and inadequate filter action.
!
Warranty and goodwill claims cannot be accepted
in the event of unit failure caused by the use of
incorrect filters.
Replacement of coarse filters GF2 and GF3
1. Detach the coarse filter (Fig. 4, item 1) together with
the angular hose fittings (Fig. 4, item 2) from the
upper and lower connection piece.
1
2
Fig. 8: Replacing the coarse filter GF2 and GF3
2. Detach both angular hose fittings from the coarse
filter by twisting gently and attach them to the new
coarse filter.
3. Attach the new coarse filter with angular hose
fittings to the connection pieces (installation
position as indicated on BEA 750).
en
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1 689 989 339 2017-12-12