Analytical Industries GPR-2500 Series Oxygen Transmitter - Manual (Page 34)

34
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
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, see Section 6 -
Maintenance.
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, and
see Section 6 - Maintenance.
Use voltmeter and determine uA or mV
output and contact factory.
High oxygen reading
Inadequate control of pressure and
flow rate
Abnormality in span gas
See Section 5 - Operation,
Getting Started,
Control of Pressure and Flow
Qualify source