Advanced Instruments Inc.
6 Maintenance
There are no moving parts in the analyzer given the modular nature of the electronics and sensor. Cleaning the
electrical contacts when replacing the sensor is the extent of the maintenance requirements of this analyzer.
Serviceability: Except for replacing the oxygen sensor, there are no parts inside the analyzer for the operator to
service. Only trained personnel with the authorization of their supervisor should conduct maintenance.
Sensor Replacement:
Periodically, the oxygen sensor will require replacement. The operating life is determined by a number of factors that
are influenced by the user and therefore difficult to predict. The sections dealing with Specification and Installation
Considerations define the normal operating conditions and expected life of the standard sensor utilized by the GPR-
1900 analyzer. As a general guideline, expected sensor life is inversely proportional to changes in oxygen
concentration, pressure and temperature.
Caution: DO NOT open the oxygen sensor. The sensor contains a corrosive liquid electrolyte that could be harmful if
touched or ingested, refer to the Material Safety Data Sheet contained in the Owner’s Manual appendix. Avoid
contact with any liquid or crystal type powder in or around the sensor or sensor housing, as either could be a form of
electrolyte. Leaking sensors should be disposed of in accordance with local regulations.
Procedure:
1.
Remove the four (4) screws securing the analyzer’s front panel.
2.
Caution: Do not discard the gaskets from the enclosure.
3.
Using the 5/16 wrench supplied loosen but do not remove the clamp bolt located
in the center of the housing with the elbows attached.
4.
Rotate the upper section of the sensor housing 90º to disengage from the clamp.
5.
Remove the upper section by pulling it straight up and place it on a smooth
surface.
6.
Remove the old oxygen sensor and dispose of it as you would a battery.
7.
Remove the new oxygen sensor from the shipping bag.
8.
Remove the red label and the gold ribbon from the PCB at the rear of the sensor.
9.
Caution: Minimize the time the sensor is exposed to ambient air.
10.
Place the new sensor in the bottom section of the sensor housing with the PCB
facing up.
11.
Place the upper section of the sensor housing over the sensor.
12.
Span Calibrate the analyzer in 20.9% ambient air, once the reading stabilizes – see above.
13.
Gently push the upper section downward and rotate 90º to engage the clamp.
14.
Finger tighten the clamp bolt and one full turn with the 5/16 wrench to compressed the o-ring seal.
Connect zero gas or low oxygen content sample gas line to purge the sensor of oxygen.
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