A virtual instrument for estimation of optimal calibration intervals by a decision reliability approach

Abstract

This paper leads to provide a methodological procedure, in order to establish optimal calibration intervals according to the reference standards. At this aim a virtual instrument has been developed to perform the proposed procedure. Generally speaking, the goal of a calibration process is to reduce out-of-tolerance occurrences to an acceptable level with respect to the desired quality target. The inevitable calibration uncertainty contributions can affect the measurement capability, and an inappropriate estimation of these aspects could lead to incorrect calibration intervals. So, the proposed methods base themselves on a statistical procedure for the evaluation of the impact of calibration process uncertainty on the decision risks. The adopted statistical approach is suitable for estimating the maintenance time needed to meet desired reliability goals. By evaluating the erroneous decision probabilities regarding the in-tolerance state within fixed limits, the statistical and metrological features of the calibration process take part in computing the most reliable interval according to an acceptable decision reliability target. The proposed methodology presents full compliance with the standards of the sector and the guidelines of ISO-9000 for quality assurance.