Operator`s manual

GAS ANALYZER 361
4. Does not read zero when sampling ambient air
If the hydrocarbons (HC) reading is above 20 ppm immediately following a zeroing and
the probe is not measuring vehicle exhaust, this is considered a Hydrocarbon Hangup
condition. This is caused by HC residues trapped somewhere in the sample system. First
re-zero the Gas Analyzer. Next, run the analyzer sampling through the sample port with
the hose off to determine if the residue is in the hose. If the buildup is in the hose, blow the
hose out with an air source that does not contain oil. Run the analyzer with the hose
attached for 10 to 30 minutes, keeping the probe free of vehicle exhaust. In addition, check
the filters for buildup. Replace if dirty. Remember that the lower filter in the Filter Bowl
gets dirty from the inside out.
5. NOx readings are erratic
If the NOx readings bounce around when little or no NOx is present or jump to 1000 or
more for no reason, most likely the sensor needs to be zeroed and calibrated again.
6. Leak Test fails
If the Leak Test fails initially, recheck any filter that may have just been serviced. Next,
remove the hose, cover the sample port and retest. If it passes, the problem is in the hose.
Otherwise, separate the filter bowl, plug the inlet, and retest. If it still fails, the problem
lies inside the Gas Analyzer.
7. Locks up
If the Tester locks up, turn off the Tester. Press ON and re-enter the previous test
environment. If the Gas Analyzer still does not communicate, recycle power to the Gas
Analyzer. Check for electrical interference sources such as spark plugs and wires, faulty
regulator, and alternators.
8. One I/P port works, but the other one does not
If one I/P port works, but the other one does not work, then the hardware is
malfunctioning. Both ports are identical and interchangeable.