Analytical Industries GPR-1000 ATEX Portable Trace PPM Oxygen Analyzer - Manual (Page 27)

27
Symptom Possible Cause Recommended Action
O
2
reading doesn’t
agree to expected
O
2
values
Pressure and temperature of the sample
is different than span gas
Abnormality in gas
Calibrate the analyzer (calibrate at
pressure and temperature of sample)
Qualify the gas (use a portable analyzer)
Erratic O
2
reading
or
No O
2
reading
Test sensor independent from analyzer
Change in sample pressure
Dirty electrical contacts in upper section
of sensor housing
Corroded solder joints on sensor PCB
from corrosive sample or electrolyte
leakage from sensor
Corroded spring loaded contact in upper
section of sensor housing from liquid in
sample or electrolyte leakage from
sensor
Liquid covering sensing area
Improper sensor selection
Presence of interference gases
Presence of sulfur gases
Unauthorized maintenance
Sensor nearing end of life
Remove sensor from housing. Using a volt-
meter set to uA output; apply the (+) lead
to the outer ring of the sensor PCB and
the (-) lead to the center circle to obtain
the sensor’s output in air. Contact factory
with result.
Sensors without PCB use mV setting.
Calibrate the analyzer (calibrate at
pressure and temperature of sample)
Clean contacts with alcohol (minimize
exposure time of MS sensor to ambient air
to extent possible)
Replace sensor and return sensor to the
factory for warranty determination
Upper section of sensor housing: Clean
contacts with alcohol, flow sample or zero
gas for 2-3 hours to flush sample system
and sensor housing
Sensor: Replace if leaking and return it to
the factory for warranty determination
Wipe with alcohol and lint free towel or
flow sample or zero gas for 2-3 hours to
flush
Replace GPR/PSR sensor with XLT sensor
when CO
2
or acid gases are present
Consult factory
Replace sensor and install scrubber
Replace sensor, obtain authorized service
Replace sensor