Calibration-curve fitting assumptions
An instrument calibration curve models indication y as a function of reference input x, such as y=a+bx+ε.
Key knowledge
An instrument calibration curve models indication y as a function of reference input x, such as y=a+bx+ε. Conventional ordinary-least-squares calibration inference assumes adequately negligible reference-input uncertainty, independent response errors and a suitable constant-variance model. If these fail, fitting and uncertainty assessment must be adapted to the actual error model, for example weighted or errors-in-variables methods where appropriate.
Values and equations
y=a+bx+ε
- y,a,ε
- Indication, intercept and residual; indication unit
- x
- Reference input; measurand unit
- b
- Calibration slope; indication unit per input unit
Conditions and scope
- Specified calibration range, stable measurement conditions and justified response model; a nonzero slope is needed for local inverse use.
- Reference values are not inherently exact. A visually straight line or high correlation alone does not validate calibration, and extrapolation adds model risk.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
National Institute of Standards and Technology (NIST)2 sources
Evidence and review
NIST/SEMATECH e-Handbook: Calibration-model assumptions: Reference-value uncertainty, response variance, independence and model assumptions. NIST/SEMATECH e-Handbook: Data analysis: Plotting calibration data, selecting a fit and validating residual behavior.
2026-10-10 · Independent AI editorial review: Independent root AI editorial review of all29 authored Measurement claims/conditions, displayed equations and37 origin relations. The original26 claims were read against41 primary source sections; all5 requested corrections and the3 affected source bindings were subsequently rechecked. Three actual scalar-nonlinear/vector/dynamic applications were read, independently differentiated or integrated, and checked against the specific additional source material described below. This is reference-content review, not human specialist certification, instrument certification or experimental replication. Full-field sign-off waits for the combined final conceptual matrix. Receipt: measurement-independent-content-review.1.
Entry details
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- measurement-calibration-fit-assumptions
- Revision
- university-core.1
- Structured reference record
- University core expansion