Analytical Industries GPR-1000 ATEX Portable Trace PPM Oxygen Analyzer - Manual (Page 26)

26
8 Troubleshooting
Symptom Possible Cause Recommended Action
Slow recovery At installation, defective sensor
Air leak in sample system connection(s)
Abnormality in zero gas
Damaged in service - prolonged
exposure to air, electrolyte leak
Sensor nearing end of life
Replace sensor if recovery unacceptable or
O
2
reading fails to reach 10% of lowest
range
Leak test the entire sample system:
Vary the flow rate, if the O
2
reading
changes inversely with the change in flow
rate indicates an air leak - correct source
of leak
Qualify zero gas (using portable analyzer)
Replace sensor
Replace sensor
High O
2
reading
after installing or
replacing sensor
Analyzer calibrated before sensor
stabilized caused by:
1) Prolonged exposure to ambient air,
worse if sensor was unshorted
2) Air leak in sample system
connection(s)
3) Abnormality in zero gas
Allow O
2
reading to stabilize before making
the span/calibration adjustment
Continue purge with zero gas
Leak test the entire sample system
(above)
Qualify zero gas (using portable analyzer)
High O
2
reading
Sampling
Flow rate exceeds limits
Pressurized sensor
Improper sensor selection
Abnormality in gas
Correct pressure and flow rate
Remove restriction on vent line or open
SHUT OFF valve completely
Replace GPR/PSR sensor with XLT sensor
when CO
2
or acid gases are present
Qualify the gas (use a portable analyzer)
Response time
slow
Air leak, dead legs, distance of sample
line, low flow rate, volume of optional
filters and scrubbers
Leak test (above), reduce dead volume or
increase flow rate