Abstract
The Guide to the Expression of Uncertainty in Measurement ( GUM) requires that measurement results are corrected for all recognized systematic effects. Therefore the answer to the comment of Kadis is unequivocally `yes`, run bias does need to be accounted for. The approach which combines a properly determined repeatability standard deviation and the uncertainty of the assessment of bias is a valid basis of the estimation of uncertainty of a measurement result. This approach produces a realisitic estimate of measurement uncertainty rather than a `safe` one.