Determination of Uncertainty in calibration of External Micrometer

Abstract

In recent years there has been a growing awareness of measurement uncertainty, mainly for two reasons. First, the ever-increasing number of laboratory accreditations requires the evaluation of measurement uncertainty, especially in the area of calibration. Second, quality system protocols get mature with process and time. This is because manufacturers ensure the reliability of their measurements through correct calibration of their test and measuring equipment. International and national regulations require calibration and testing laboratories to provide result of measurement uncertainty. Calibration of the measuring instrument is the process in which the readings obtained from the instrument are compared with the standard values in the laboratory at several points along the scale of the instruments i.e. micrometer, gauges, calipers etc. In general, a calibration without information about the uncertainty of these estimates is incomplete. Calculating measurement uncertainty is an attempt to reasonably limit the results of measurements as referring to standard operating procedures. Since each measurement only provides a result of the outcome, the main requirement of the uncertainty estimation is to make reader confident that reading is within stated range. Proper calibration involves more than just estimating measurement uncertainty. It also requires that the estimated value is small compared to the stated accuracy of the meter.