Method for calibrating line standards with marks, with nominal length up to 1000 mm: Uncertainty budget

摘要

This paper describes a modern method used for thecalibration of line standards with marks using a longitudinal comparator with an He-Ne frequency-stabilized laser source, and the subsequent estimation of the errors which occur during the measurement of line standards with such a longitudinal comparator. The author's contribution consists of: (1) the analyses of the sources of error which occur during the measurement due to the line standard, longitudinal comparator, electronic equipment and temperature; (2) the estimation of the measurement uncertainty budget according to the specifications of the GUM [1]; and (3) finding a better longitudinal comparator construction solution to increase the performance of the measurement of line standards, consisting in replacing the optical microscope with a modern viewing model equipped with a CCD camera and custom software for capturing and analyzing the image.