Adjusting The Analogue Output - Crowcon IR Display Instructions D'installation, D'utilisation Et De Maintenance

Possible reasons for failure of calibration:
a. Lamp or detector failure.
b. Instrument requires zeroing first (e.g. zero shift due to obscuration fault).
c. Gas reading is out of acceptable range (Incorrect gas or gas level applied).
Click the 'Enter' button.
Clear the IRmax of the calibration gas. The display will track the level of gas present in the
gas chamber.
When the level has returned to 'normal', click the 'Enter' key to return the display to the menu.
The inhibit mode will be removed, and the gas level will display as in normal operation.
*Inhibit mode suppresses the output signal while the IRmax is being calibrated to avoid
triggering alarms on a control system while significant levels of gas are applied. The
'operational inhibit', the default output of the IRmax in inhibit mode, is usually 0 %LEL.

9.5 Adjusting the analogue output

The display allows two adjustments to be made to the analogue output of the IRmax. Use
the TRIM function to shift the analogue output at zero gas. The SPAN function changes
the range of the analogue output i.e. the difference between output at zero gas
concentration (%LEL) and the output at maximum gas concentration (%LEL).
Analogue output
Zero output
0
Gas level (%LEL)
Controlling the IRmax Controlling the IRmax
Range
100
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