2. Measurement Process Characterization
2.3. Calibration
2.3.3. What are calibration designs?

2.3.3.3.

Uncertainties of calibrated values

Uncertainty analysis follows the ISO principles

This section discusses the calculation of uncertainties of calibrated values from calibration designs. The discussion follows the guidelines in the section on classifying and combining components of uncertainty. Two types of evaluations are covered.

1. type A evaluations of time-dependent sources of random error
2. type B evaluations of other sources of error

The latter includes, but is not limited to, uncertainties from sources that are not replicated in the calibration design such as uncertainties of values assigned to reference standards.

Uncertainties for test items

Uncertainties associated with calibrated values for test items from designs require calculations that are specific to the individual designs. The steps involved are outlined below.

Outline for the section on uncertainty analysis

• Historical perspective
• Assumptions
• Example of more realistic model
• Computation of repeatability standard deviations
• Computation of level-2 standard deviations
• Combination of repeatability and level-2 standard deviations
• Example of computations for 1,1,1,1 design
• Type B uncertainty associated with the restraint
• Expanded uncertainty of calibrated values