Operating Method; Initial Commissioning; Connecting To An Test System - Bosch ETT 8.70 Instrucciones De Manejo

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 automa-
tically released for carrying out measurements.
3.3.3 Drift correction
The analyser will automatically carry out a system test with
ambient 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 concentra-
tions of HC, CO, CO and oxygen measured. Precise oxygen
2
measurement 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
provided (20).
Oxygen measurement is automatically adjusted to an oxygen
content of 20.9 % by volume of air. It can be switched off.
The O sensor is a part subject to wear.
2
22
)
vrai
.
2
sensor. This
2
3.4

Initial commissioning

! ! ! ! ! Min. height of installation location: 250 mm from floor
Min. length of outlet hoses: 300 mm
i i i i i
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
For a hose connection plan, see Fig. 1.
- Connect the exhaust sampling sensor to the prefilter (8) using
the 30 cm viton hose (7).
- Connect the sampling hose (6) to the prefilter.
- Connect the sampling hose to the gas intake (5) on the
analyser.
! ! ! ! ! Connect 3 70 cm PVC hoses (10/11/12) to the gas
outlets.
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.
- Connect the analyser to a properly earthed two-pole-and-earth
socket outlet using the power lead supplied.
3.5

Connecting to an test system

The values measured with the exhaust-gas analyser are automa-
tically transferred to the test system.
To do this, the exhaust-gas analyser must be connected to the test
system via the serial port (22). The parameters of the exhaust-gas
analyser are set by the respective test system connected.
OIML CLASS 1
PTB
18.10
18.10
O
2
COM 1
> 250 mm
459571/2P