Sampling, Procedure – Analytical Industries GPR-1800 IS ATEX Trace PPM Oxygen Transmitter User Manual
Page 32
Advanced Instruments, Inc
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MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
CALIBRATION
CONFIG ALARMS
BYPASS ALARMS
>>>
CALIBRATION
SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
OUTPUT SPAN
OUTPUT ZERO
Advance the reverse shade cursor using the ARROW keys to highlight DEFAULT SPAN.
Press the ENTER key to select the highlighted menu option.
The following display appears
100.0
OUTPUT SPAN OFFSET
PRESS UP OR DOWN
TO CHANGE VALUE
ENTER TO SAVE
MENU TO RETURN
The default setting of 100 illustrates no adjustment to the analog output signal. Compute the adjustment
value as described in Appendix B or consult the factory. The true adjustment value must be determined
empirically by trial and error. Adjust the initial value to above 100 to increase the 20 mA analog signal value
or decrease it below 100 to decrease the 20 mA analog signal.
Press the ENTER key to advance the underline cursor right or press the MENU key to advance the
underline cursor left to reach to the desired digit of the OUTPUT SPAN OFFSET value.
Press the ARROW keys to enter the OUTPUT SPAN OFFSET value.
Repeat above steps until the complete OUTPUT SPAN OFFSET value has been entered.
Save the adjustment value by pressing the ENTER key or abort by pressing the MENU key.
The system returns to the SAMPLING mode.
Sampling
GPR-1800 IS Oxygen Transmitter requires a positive pressure to flow the sample gas across the sensor to
measure the oxygen concentration in a sample gas. If not available see Pressure & Flow section.
Procedure
Following calibration, the transmitter returns to the SAMPLE mode.
Select the desired sampling mode - auto or if manual, the range that provides maximum resolution – as
described above.
Use metal tubing to transport the sample gas to the transmitter.
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
sample input port.