National Physical Laboratory

Why do my stylus and optical surface measuring instruments often give different results? (FAQ - Length)

Stylus (mechanical contact) and optical (non-contact) instruments operate on different physical principles and will always tend to differ in the results they give for a surface. However, with the right calibration artefacts and if good practice is applied, the instruments can be corrected so that their results agree. Where possible a calibration artefact should closely match the surface being measured.
Last Updated: 25 Mar 2010
Created: 18 Jul 2007


Please note that the information will not be divulged to third parties, or used without your permission