UNCERTAINTY MODELING IN MASS COMPARISONS

To evaluate uncertainty in mass measurements with accuracy and in acco rdance with recent international documents, a general model is develop ed, which takes account of the various contributing quantities in a mu ltivariate context. On this basis, the variance-covariance matrix of t he in-vacuo mass differences is constructed in its general form and ta ilored for application to some of the most commonly adopted weighing m ethods. The usual assumption of equal-variance, uncorrelated observati ons is shown to be inappropriate for mass comparisons.