Analytical Industries GPR-2500 Series Oxygen Transmitter - Manual (Page 30)

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25. Both the Zero Calibrate and Span Calibrate functions result in the following displays:
PASSED
CALIBRATION
OR
FAILED
CALIBRATION
26. If the calibration is successful, the transmitter returns to the SAMPLING mode after 30 seconds.
3.3
%
AUTO SAMPLING
10% RANGE
24.5 C 100 KPA
27. If the calibration is unsuccessful, return to the SAMPLING mode with span gas flowing through the transmitter,
make sure the reading stabilizes and repeat the calibration before concluding the equipment is defective.
28. Before disconnecting the span gas line and connecting the sample gas line, restart if necessary the flow of
sample gas and allow it to flow for 1-2 minutes to purge the air inside the line.
29. Disconnect the span gas line and replace it with the purged sample gas line.
30. Wait 10-15 minutes to ensure the reading is stable and proceed to sampling.
Sampling
GPR-2500/2500MO Oxygen Transmitter requires positive pressure to flow the sample gas by the sensor to measure
the oxygen concentration in a sample gas. If not available see Pressure & Flow section.
Note: Prematurely zeroing the transmitter can cause the transmitter to display a negative reading in both the
ZERO and SAMPLE modes.
Procedure:
Following calibration the transmitter returns to the SAMPLE mode after 30 seconds.
1. Select the desired sampling mode - auto or if manual, the range that provides maximum resolution – as
described above.
2. Use metal tubing to transport the sample gas to the transmitter.
3. The main consideration is to eliminate air leaks which can affect oxygen measurements above or below the
20.9% oxygen concentration in ambient air - ensure the sample gas tubing connections fit tightly into the 1/8”
male NPT to tube adapter, and, the NPT end is taped and securely tightened into the mating male quick
disconnect fittings which mate with the female fittings on the transmitter