How to set the range of combustible gas instruments
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A combustible gas detector for measuring methane was installed on site. If the signal sent to the DCS is a 4-20mA signal, how should the range of the DCS instruments be set?
0-4mA, 100-20mA, classified according to a linear relationship
Of course, it has to be determined based on the output range of the instrument.
0-100% LEL corresponds to 4-20 mA
Generally, the maximum range is set to twice the lower limit of the explosion limit; this ensures accuracy in measurements below the explosion limit as well as accuracy in measurements above it
One cannot focus only on the results. Understand the meaning of the LEL unit, and you’ll understand everything.