Analytical Industries GPR-2500 A Oxygen Analyzer - Manual (Page 22)

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Main Menu:
Access the MAIN MENU by pressing the MENU key:
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE
24.5 C 100 KPA
Range Selection:
The GPR-2500A transmitter is equipped with four (4) standard measuring ranges (see specification) and provides
users with a choice of sampling modes. By accessing the MAIN MENU, users may select either the AUTO SAMPLING
(ranging) or MANUAL SAMPLING (to lock on a single range) mode.
Note: For calibration purposes, use of the AUTO SAMPLE mode is recommended. However, the user can select the
full scale MANUAL SAMPLE RANGE for calibration as dictated by the accuracy of the analysis required – for
example, a span gas with an 8% oxygen concentration with the balance nitrogen would dictate the use of the 0-
10% full scale range for calibration and a 0-10% measuring range.
Procedure - Auto Sampling:
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight AUTO SAMPLE.
3. Press the ENTER key to select the highlighted menu option.
4. The display returns to the sampling mode:
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
CALIBRATE
24.5 C 100 KPA
3.3
%
AUTO SAMPLING
10% RANGE
24.5 C 100 KPA
The display will shift to the next higher range when the oxygen reading (actually the sensor’s signal output)
exceeds 99.9% of the upper limit of the current range. The display will shift to the next lower range when the
oxygen reading drops to 85% of the upper limit of the next lower range.
For example, if the transmitter is reading 1% on the 0-10% range and an upset occurs, the display will shift to the
0-25% range when the oxygen reading exceeds 9.9%. Conversely, once the upset condition is corrected, the
display will shift back to the 0-10% range when the oxygen reading drops to 8.5%.