Model-based analysis of key comparisons applied to accelerometer calibrations

The concept of a model-based analysis of key comparisons is proposed and illustrated by applying it to data from a regional key comparison of accelerometer calibrations on a scale of frequencies. A physical model of the frequency dependence of the accelerometers' sensitivities is used to calculate reference values. The parameters of the physical model are determined by weighted least squares, and the resulting model is shown to conform with the data. Uncertainties associated with the reference values calculated by the physical model are smaller than those associated with reference values obtained by standard analysis. This can lead to a more favourable assessment of the degree of equivalence of single laboratory measurement values as expressed by calculated E-n-numbers. The degree of equivalence of single laboratory measurement values is quantitatively calculated by both model-based analysis and standard analysis, and the results obtained and their differences are discussed.