Analytical Industries GPR-1900 Series Trace PPB Oxygen Analyzer - Manual (Page 17)

Advanced Instruments Inc.
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MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS
BYPASS ALARMS
Range Selection
The GPR-1900 analyzer 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 optimal accuracy, a span gas
with an 800 ppm oxygen concentration with the balance nitrogen would dictate the use of the 0-1000 ppm full scale range for
calibration for analysis below 100 ppm, whereas, 80 ppm span gas is acceptable but not “optimal”, see Calibration & Accuracy.
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
CALIBRATION
CONFIG ALARMS
BYPASS ALARMS
3.3
PPM
AUTO SAMPLING
100 PPM RANGE
24.5 C
LO1 2 PPM 10 PPM HI2
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 analyzer 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%.
Manual Sampling:
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor using the ARROW keys to highlight MANUAL SAMPLE.
3. Press the ENTER key to select the highlighted menu option.
4. The following display appears: