Free engineering calculators and unit convertersceo@instrumentationblog.in
Calibration · Glossary

What is a Calibration Curve?

fitted relationCalibration

A calibration curve is a fitted relationship between instrument reading and true value, used to correct readings.

Advertisement

Calibration Curve Explained

Data points from a calibration are fitted with a line or polynomial by least squares. The fitted equation converts readings to corrected values.

Analysers and laboratory instruments rely on calibration curves; smart transmitters use internal characterisation.

Calibration Curve Formula

m = Σ(x − x̄)(y − ȳ) ÷ Σ(x − x̄)²,   c = ȳ − m x̄
xreference values
yreadings
m, cslope and intercept
Advertisement

Calculators for Calibration Curve

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

Free Downloads

Free downloadMeasurement Uncertainty Budget Excel SheetFree download in Excel and PDF.

Frequently Asked Questions

What is a Calibration Curve?

A calibration curve is a fitted relationship between instrument reading and true value, used to correct readings.

Line or polynomial?

Use the simplest that fits within uncertainty; high order fits can wander between points.

What is R²?

A measure of fit quality; close to 1 means points lie close to the curve.

You May Also Like

Learn more on the blog

Instrumentation calibration and troubleshooting guide

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

Read Full Article

Related Terms

Calibration termLinearityLinearity is how closely an instrument output follows a straight line between input and output; non…Calibration termCalibration CorrectionA calibration correction is the value added to an instrument reading to obtain the corrected value; it is…Calibration termZero and Span ErrorZero and span error describe an instrument whose reading is offset at the bottom of the range (zero) or…

More Calibration Terms

Calibration termCalibration CertificateA calibration certificate is a formal document reporting calibration results, the reference used,…Calibration termISO/IEC 17025ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories.Calibration termCalibrationCalibration is the comparison of an instrument reading with a known reference standard, recording the…Calibration termAccuracyAccuracy is how close a measurement is to the true value; in specifications it is the maximum expected error.Calibration termAccuracy SpecificationAn accuracy specification states how an instrument maker defines its maximum error, such as % of span, %…Calibration termPrecisionPrecision is how closely repeated measurements of the same quantity agree with each other, regardless of…

All calibration terms · Full glossary A to Z

Advertisement