Analytical Industries GPR-1500 A Series Trace PPM Oxygen Analyzer - Manual (Page 36)

Advanced Instruments, Inc
36
Symptom Possible Cause Recommended Action
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
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 transmitter (calibrate at
pressure and temperature of sample)
Qualify the gas (use a portable analyzer as
a second check)
Erratic O
2
reading
or
No O
2
reading
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
Unauthorized maintenance
Sensor nearing end of life
Calibrate the transmitter (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 water, wipe contacts with
clean paper towel and flush system and
sensor housing with dry gas
Sensor: Replace if leaking and return it to
the factory for warranty determination
Wipe with lint free towel or flow dry sample
or zero gas for 2-3 hours to flush out
condensation
Consult factory for recommendation.
Replace sensor and install scrubber
Consult factory.
Replace sensor
Erratic O
2
reading
or
Negative O
2
reading
Pressurizing the sensor by
flowing gas to the sensor with
the vent restricted or SHUT
OFF valve closed and Zero the transmitter. If not successful
replace the sensor