4.4 Sampling the Exhaust Gas
Once the zero calibration and test procedures have been completed and the fuel has been selected (See
Section 5.2.2) the probe can be inserted into the desired vehicle exhaust.
Ensure the probe is inserted into the exhaust pipe so as to not allow air into the probe. The exhaust of a car
can pulse, especially at low RPM, drawing air in causing bad readings, ensure the flexible probe is fully
inserted and the clip attached to the exhaust pipe.
4.5 Turning the pump ON/OFF
The analyzer is fitted with a pump to draw gas from the vehicle exhaust. To conserve battery power, switch
off the pump when you are not taking a measurement. Gas values may drift slightly when the pump is
turned off but should return to zero when the pump is turned on again. Manually zero the analyzer if it does
not return to zero.
Use the key to turn ON and OFF the pump.
CERTAIN ANALYZERS ONLY
The analyzer will block readings while the pump is off and display ‘----‘ on all gas channels. It will also
display PUMP OFF every 30 seconds.
It is recommended that the analyzer samples fresh air for at least 60 seconds before the pump is turned off.
9
PUMP OFF
HC
ppm
vol . . .- - - -
CO2
%
vol . . . .- - - -
O2
%
vol . . . .- - - -
Vehicle Exhaust