What is the difference between range and span?

Field Instrumentation
1

Explain how range is different from span

2

Range - is minimum value to maximum value

Span - is the difference between range values. ( Maximum to a minimum)

Span is one number, the difference between the upper range value and lower range value. The range is usually the two values where a device produces 4ma and 20ma.

Span – It can be defined as the range of an instrument from the minimum to maximum scale value

Range – It can be defined as the measure of the instrument between the lowest and highest readings it can measure.

The range is the upper value and the lower value of the instrument whereas span is the algebraic difference between the upper range value and the lower range value, e. g 4-20mA is the range then 16mA is the span.

Here is an example:

The range could be -10 PSI to +20 PSI. That is a span of 30 PSI.