Operating Method; Initial Commissioning - Bosch ETT 008.71 Betriebsanleitung

3.3

Operating method

3.3.1
Warming-up period
The warming-up period of the unit lasts 3 minutes. No analysis is
possible during this period. Afterwards, the measuring instrument
carries out a system check (calibration) using ambient air.
3.3.2 Measurement
After the pump is switched on, the zero point of the analysis system
is automatically adjusted using ambient air (zero gas). Duration: 30
sec. After this adjustment, the instrument is automatically released
for carrying out measurements.
3.3.3 Drift correction
The analyser will automatically carry out a system test with am-
bient air 15 minutes after analysis has commenced. If analysis is
being carried out at that time, the test will be postponed until its
completion.
3.3.4 „CAL" system test
The analyser switches a solenoid valve over to ambient air for
the system test. Zero gas is used for flushing the unit for 30
seconds.
Hydrocarbons are removed from the inducted ambient air by an
activated charcoal filter.
The drift of the oxygen measurement is monitored and adjusted.
3.3.5
Air ratio measurement
The analyser calculates the lambda air ratio from the concentrations
of HC, CO, CO and oxygen measured. Precise oxygen measure-
2
ment is important for the purposes of lambda calculation.
Both the excess-air factor (lambda) and oxygen measurement
must be activated.
3.3.6 Corrected CO concentration (CO
The analyser will calculate the corrected concentration of CO
(CO ) from the concentration of CO and CO
vrai
Allowance is then made for leaks in the exhaust system.
3.3.7
Oxygen measurement
The exhaust-gas analyser is equipped with an O
sensor is screwed to the rear of the analyser in the socket pro-
vided (20).
Oxygen measurement is automatically adjusted to an oxygen con-
tent of 20.9 % by volume of air. It can be switched off.
The O sensor is a part subject to wear.
2
24
3.3.8 NO measurement (optional accessory)
The analyser can be fitted with an NO sensor. The sensor is
screwed to the rear of the device in the designated location
(Fig. 2, Pos. 23) (see Installation Manual 1 689 978 360 for re-
trofit kit 1 687 001 440). The NO measurement is automatically
calibrated with the ambient air. A regular re-adjustment with NO
test gas is required. The measurement can be disconnected.
The NO sensor is a wearing part.
3.4
!
i
For a hose connection plan, see Fig. 1.
- Connect the exhaust sampling sensor to the prefilter (8) using
- Connect the sampling hose (6) to the prefilter.
- Connect the sampling hose to the gas intake (5) on the analy-
)
vrai
!
.
2
!
sensor. This
2
- Connect the analyser to a properly earthed two-pole-and-earth

Initial commissioning

Min. height of installation location: 250 mm from floor
Min. length of outlet hoses: 300 mm
These specifications must be observed to ensure that the
condensate generated constantly flows off, the accuracy of
measurement is guaranteed and that the measuring system
is adequately protected again contamination.
GF4 AF1 GF3 GF2
cal
> 300 mm
the 30 cm viton hose (7).
ser.
Connect 3 70 cm PVC hoses (10/11/12) to the gas out-
lets.
Lead the hoses into an open container to collect conden-
sation.
Observe the voltage specifications shown on the rating
plate!
The exhaust-gas analyser can only be reset to another
voltage rating by a Bosch service agency.
socket outlet using the power lead supplied.
OIML CLASS 1
PTB
18.10
18.10
O NO
2
COM 1
> 250 mm
459571/2K