Analytical Industries GPR-3500 MO Portable Oxygen Analyzer - Manual (Page 26)

Advanced Instruments Inc.
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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 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 damp lint free towel.
Consult factory
Consult factory
Replace sensor and/or consult factory
High oxygen reading
Inadequate control of flow rate
Abnormality in span gas
See Pressure and Flow
Qualify source