Analytical Industries GPR-3100 Series Oxygen Purity Analyzer - Manual (Page 30)

Advanced Instruments Inc.
5 Operation
GPR-3100 Rev 2/05 23
To avoid damaging the sensor or sample system observe the following guidelines:
1. Drawing a vacuum on the sensor by pressurizing the analyzer: Results when sample gas flows into the
analyzer, builds up within the analyzer sample system because the SHUT OFF valve is closed or the outlet
vent is restricted, and, is suddenly released when the blockage is removed. This sudden release of
backpressure draws a vacuum on the sensor.
2. Drawing a vacuum on the sensor when using a sampling pump or eductor downstream of the
analyzer.
Special considerations include:
Sampling - before activating the pump or eductor, assure the FLOW valve and SHUT OFF valve are
completely open. Set the sample flow rate to 2 SCFH on the flow indicator by adjusting the PUMP
BYPASS valve.
Span calibration - deactivate the pump or eductor, set the span flow rate to 2 SCFH on the flow indicator
by adjusting the FLOW valve. After span calibration is complete, open the FLOW valve completely before
activating the pump or eductor.
Note: The vacuum generated in 1 or 2 above may exceed the recommended limit and stress the sensor’s
seals to the point of rupture causing the sensor to leak electrolyte (voiding the sensor warranty).
Electrolyte leakage may damage the electrical contacts of the upper section of the sensor housing
assembly (if not removed quickly) dictating replacement of the entire upper assembly.
3. Subjecting the analyzer to high positive pressure can damage the sensor, pumps or other flow system
components.
4. Introducing calibration span gas from a pressurized cylinder without pressure regulation: Results in an
inaccurate calibration and possible damage to the analyzer’s scrubber and pumps.
5. NEVER block the outlet vent of the sample gas on the side of the analyzer: This includes pressing your
finger over the outlet vent to confirm the flow indicator is operating.
6. The pressure at the vent outlet must be lower than the inlet pressure. Normally, the vent is at
atmospheric pressure. Otherwise a back pressure regulator may be required to stabilize the pressure at
the sensor.
Standby & Storage
The analyzer has no special storage requirements. If storing for an extended period of time, disconnect
the power to the analyzer.