Calculating Burn in Duration to Attenuate Non Linear Sensor Aging
Calculate sensor burn-in time by dividing equivalent operating hours at the infant drift inflection point by the temperature-derived Arrhenius acceleration factor.
JCGM 100 Evaluation
Uncertainty Framework
Standardized mathematical procedures established by international metrology organizations govern the expression and quantification of measurement uncertainty across scientific fields. Within sensor calibration and testing laboratories, JCGM 100 evaluation provides a systematic methodology for combining random statistical variations with systematic calibration limits into a unified uncertainty budget. Standardized framework rules establish uniform procedures for identifying, evaluating and reporting measurement uncertainties associated with sensor output readings.
The coverage of this methodology applies to physical measurements where input parameters convert to output values through a clear mathematical functional relationship.
Statistical Derivation
Evaluation of uncertainty components divides sources into Type A evaluations based on statistical analysis of series of observations and Type B evaluations based on scientific judgement and calibration certificates. In precision calibration, JCGM 100 evaluation applies partial derivatives to the functional measurement model to determine sensitivity coefficients for each input quantity. Type A uncertainties draw from standard deviations of repeated measurements, while Type B uncertainties use manufacturer specifications, reference standard tolerances and environmental limits.
Combining these standard uncertainties requires taking the square root of the sum of squared individual variances weighted by their respective sensitivity coefficients. When input variables exhibit statistical correlation, covariance terms must be included in the combined variance calculation to avoid underestimating total measurement uncertainty. The final result converts to an expanded uncertainty by multiplying the combined standard uncertainty by a coverage factor that defines a specific confidence interval.
Variance Component
Uncontrolled ambient temperature swings, power supply noise and reference instrument drift contribute distinct variance components to the total uncertainty budget. Temperature fluctuations expand Type B uncertainty limits when environmental control bounds exceed standard laboratory reference specifications. Quantifying transducer hysteresis and non repeatability requires repeated calibration runs that generate Type A statistical data under controlled operating conditions.
Expanded Scope
Calculated uncertainty values hold validity only within the specific environmental ranges, excitation voltages and pressure limits defined in the measurement model. Applying a JCGM 100 evaluation outside these declared boundary conditions invalidates the reported expanded uncertainty figures.