2.
Measurement Process Characterization
2.5. Uncertainty analysis 2.5.6. Uncertainty budgets and sensitivity coefficients
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From measurements on check standards | If the temporal component of the measurement process is evaluated from measurements on a check standard and there are \(M\) days (\(M = 1\) is permissible) of measurements on the test item that are structured in the same manner as the measurements on the check standard, the standard deviation for the reported value is $$ s_{reported \, value} = \frac{1}{\sqrt{M}} s_2 $$ with degrees of freedom \( \nu_2 = K - 1\) from the \(K\) entries in the check standard database. | ||
Standard deviation from check standard measurements | The computation of the standard deviation from the check standard values and its relationship to components of instrument precision and day-to-day variability of the process are explained in the section on two-level nested designs using check standards. | ||
Sensitivity coefficients | The sensitivity coefficients are: \( a_1 = 0 ; \, a_2 = \sqrt{\frac{1}{M}} \). |