Adjust The Range Of The Output (Span) - Crowcon IR Display Instructions D'installation, D'utilisation Et De Maintenance

9.5.2 Adjust the range of the output (SPAN)

The SPAN adjustment alters the gain of the analogue output.
Analogue output
20.4 mA
20.2 mA
Zero output
NOTE: 3mA of adjustment is available for the span signal output.
For example, if, when calibrated, a 50% LEL gas reading is displayed but the output signal
does not register as exactly half-scale (e.g. 12mA), the SPAN function can be used to
modify the signal.
Press the 'Enter' key to display the current analogue output.
Use the 'Up' and 'Down' keys to adjust the reading.
If the operation times out before the change is accepted, the analogue output will revert
to the original value.
NB: THIS GRAPH IS NOT DRAWN TO SCALE
0
Gas level (%LEL)
Original analogue output response to gas
Analogue response to gas after reducing span by 0.2 mA
Controlling the IRmax Controlling the IRmax
Span
adjustment
of -0.2 mA
100
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