Formula for Process Variable to Percentage Conversion

Calculate the equivalent Percentage for any given Process variable. For conversion, we need transmitter Lower Range Value and Upper Range Value.

Process Variable to Percentage Conversion

Formula:

Percentage %  =   ((Process Variable – LRV)/Span)(100)

Span = URV – LRV

Where

URV upper range value
LRV lower range value

Example: 

An electronic Pressure transmitter is ranged -1 to 5 Bar and has a 4-20 ma. Calculate the Percentage output by this transmitter if the measured Pressure is 1 Bar

Span = 5 – (-1) = 6

Percentage % = ((Process variable – LRV)/Span)(100)

Percentage % =((1-(-1))/6)(100)

Percentage % = 33.33 %

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