A stochastic approach to the determination of calibration intervals

The paper discusses a class of stochastic models for evaluating the optimal calibration interval in measuring instruments. The model is based on the assumption that the calibration condition of a measuring instrument can be traced by means of an observable parameter. The observable parameter is undergoing a stochastic drift process. The paper introduces and compares stochastic drift models of different nature, and estimates the first passage time of the drift process across an absorbing barrier whose value is set equal to the allowed tolerance on the observable parameter. The calibration interval is determined as a suitable percentile of the distribution function of the first passage time