Calculation of uncertainty of measurement in machine vision case: a system for the calibration of dial indicators

Using automatic machine vision-based systems, the calibration of measurement instruments can be extended. With machine vision it is possible to check hundreds of points on the scale of a dial indicator, giving new insight into error sources of the dial indicator. The frequency information of the error curve can be studied by calculating the Fourier transform. In the development of machine vision based systems, the calculation of uncertainty of measurement is often forgotten or neglected. Real confidence in a measurement is achieved only by systematic documentation and calculation of the uncertainties. This article describes a machine vision based system for the calibration of dial indicators, with emphasis on the calculation of measurement uncertainty