Analytical Industries GPR-2900 Series Oxygen Analyzer - Manual (Page 31)

Advanced Instruments Inc.
31
8 Troubleshooting
Symptom Possible Cause Recommended Action
Reading does not reflect
expected values
Sensor was not calibrated at the pressure,
flow rate and temperature anticipated in
the sample gas stream
Recalibrate the analyzer using the known oxygen
content of ambient air, 20.9%, and if the sensor
responds we should presume it is correct.
Oxygen reading drifts
toward zero or significant
number of turns of the
span control adjustment is
required to calibrate the
analyzer.
Indication sensor is nearing the end of its
useful life
Replace sensor
Slow response time
Erratic oxygen reading
No oxygen reading
Liquid covering sensing membrane
Presence of interference gases.
Unauthorized maintenance
Defective electrical connection
Sensor failure
Gently remove with alcohol and lint free towel.
Consult factory, replace sensor
Use voltmeter and determine uA or mV output
and contact factory.
High oxygen reading
Inadequate control of pressure and
flowrate
Abnormality in span gas
See Installation Considerations, section 5
Qualify source by recalibrating the analyzer with
the known oxygen content of ambient air, 20.9%