Calibration · Glossary

What is Linearity?

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Linearity is how closely an instrument output follows a straight line between input and output; non linearity is the maximum deviation.

Linearity Explained

Linearity can be referenced to a best fit straight line (independent), a line through the end points (terminal) or a line through zero. The method changes the number, so check which is used.

Smart transmitters correct most sensor non linearity internally.

Linearity Formula

Non linearity = max |R − (m x + c)| ÷ Span × 100

R	reading
m, c	slope and intercept of the reference line
x	input

Calculators for Linearity

CalculatorLinearity Error CalculatorFree online calculator with formula and worked example.CalculatorCalibration Curve CalculatorFree online calculator with formula and worked example.

Free Downloads

Free downloadPressure Transmitter Calibration Report FormatFree download in Excel and PDF.

Frequently Asked Questions

What is Linearity?

Linearity is how closely an instrument output follows a straight line between input and output; non linearity is the maximum deviation.

Which linearity method is strictest?

Terminal based usually gives the largest value; best fit gives the smallest.

Can zero and span fix non linearity?

No, they shift and tilt the line; a curved error remains.

Learn more on the blog

Instrumentation calibration and troubleshooting guide

A practical guide on instrumentationblog.in with more detail on linearity and how it is applied on real plants.

Read Full Article

More Calibration Terms

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