Analytical Industries GPR-1000 ATEX Portable Trace PPM Oxygen Analyzer - Manual (Page 24)

24
6 Maintenance
Generally, cleaning the electrical contacts or replacing filter elements is the extent of the maintenance
requirements of this analyzer.
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 Features & Specifications define the normal
operating conditions and expected life of the standard sensor utilized by the GPR-2000 Series analyzer. Expected
sensor life is inversely proportional to changes in oxygen concentration, pressure and temperature.
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.
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. 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 hinged front panel of the transmitter and raise it up 180º until it locks
into position.
2. Caution: Do not remove or discard the gaskets from the enclosure. Failure to reinstall the gasket will void the
NEMA rating.
3. Locate the connector at the end of the four (4) wires running to the sensor from the PCB.
4. With your left fore finger and thumb, grasp the back end of the male connector attached to the sensor.
5. With your right fore finger and thumb, grasp the sides of the section of the female connector where the four
(4) wires from the sensor terminate.
6. Separate the connector - hold the male connector section with your left hand while gently pulling and wiggling
the female connector section with your right hand until it unlocks.
7. Unscrew the old sensor from the threaded hole in the sensor flow housing.
8. Open the barrier bag containing the new sensor.
9. If the sensor is equipped with a shorting loop, remove the shorting wire from the pins of the female socket
attached to the new sensor.
10. Place the new sensor on a flat surface exposed to ambient air.
11. Align the holes and tabs of the female connector with the 4 pins and vertical
support of the male connector.
12. Push the female connector with the wire cable to the cable onto the male
section until they snap together.
13. Once the reading stabilizes, calibrate the transmitter in 20.9% ambient air as
described in section 5 Operation Span Calibration.
14. Once calibrated, temporarily separate the connectors and disconnect the sensor.
15. Immediately screw the new sensor, finger tight plus 1/2 turn, into the flow
housing and reconnect the sensor.
16. Replace the front cover of the transmitter, replace the gasket to maintain CE approval and NEMA 4 rating and
tighten the four (4) screws to secure the front cover.
17. The analyzer will OVER RANGE for a short period of time as indicated by the graphical LCD display.
18. Connect zero gas or low oxygen content sample gas line to purge the sensor of oxygen.