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10.2 HC residue check (Certain analyzers only)
Hydrocarbon is a very ‘sticky’ gas and can cling to tubing in the analyzer or probe. If HC % vol reading does
not go below 20 ppm when in fresh air following a test then a residue check will be requested. Repeat tests
will be carried out until the reading is below 20 ppm.
The HC residue check procedure is as follows:
As instructed remove the probe from the exhaust and detach the water trap and particle filter housing from
the instrument. Fit the carbon filter element in place of the water trap housing, press
when in place.
NOTE!
The analyzer will not continue with the test if it does not detect the carbon filter element is
in place. Use of the analyzer is prohibited if the filter is not used and a successful HC residue
check not completed.
During this check it is advisable to perform the following maintenance:
• Change the particle filter and clean the inside of the housing.
• Clear the probe line using a compressed air line. Note! This must only be done with the probe
removed from both analyzer and vehicle.
If the analyzer cannot detect a reduction in the HC level to within preset limits then it will try again from the
screen shown above. If the analyzer continues to fail the test contact your service agent for advice.
If the HC residue check is successful the following screen will be displayed.
Once the check is complete the screen will return to the
MAIN DISPLAY
. Remove the carbon filter element
and store in the instrument case. Reconnect the water trap housing and probe.
HC RESIDUE CHECK
REMOVE EXHAUST PROBE
FIT CARBON FILTER
THEN PRESS ENTER
HC RESIDUE CHECK
PASSED
REMOVE CARBON FILTER
THEN PRESS ENTER