ION ARA H2S-H Instrument User Manual page 18

At this point click the calibration cap onto the sensor inlet port then open the valve on the manual fixed flow
regulator. The screen on the ARA will then display C90 and begin counting down C89, C88 etc for
approximately 20 seconds for the Oxygen ARA and 90 seconds for the other versions.
NOTE: If its position is moved away from the IR Link after C90 countdown starts, the ARA will still continue to
calibrate but the IR software will not acknowledge a pass or fail calibration. Ideally, the ARA needs to be
aligned with the IR Link during the complete calibration procedure.
NOTE: If no gas is connected within approximately 45 seconds, the calibration procedure will fail and display
the below message.
Pioneering Gas Sensing Technology.
ARA Instrument User Manual V1.1
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