The paper is devoted to research of the linear drift influence of repeated observations results on the statistical evaluation of the standard uncertainty calculated from these results. The analytical formula which describes the drift contribution is obtained. It is shown, that for significant volume sample the contribution value is proportional to the time of obtaining the sample. The minimal sample volume which allows to minimize the linear drift contribution to a statistical evaluation of a standard deviation is established. The irrelevance criterion of the regular linear drift of repeated observations results in the type A standard uncertainty evaluation is determined.
the measurement uncertainty, the statistical evaluation, the linear drift, the standard uncertainty