Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Standardized Performance Testing Metrics for Optical Coordinate Measurement Systems



Steven D. Phillips


Optical probing technology on coordinate measuring machines (CMMs) operates significantly differently from discrete point probing associated with tactile probing CMMs hence manufacturers of this technology seek to use different testing artifacts for standardized performance testing. However, the standardized performance metrics which describe the CMM’s measurement accuracy need to be comparable to other CMMs regardless of the probing technology. This paper examines several different metrics that can be computed from the test results of CMMs with optical probes and theses metrics are compared for equivalency to the canonical results specified by ISO and ASME standards used for tactile CMMs. A derivation is presented which motivates a more detailed computer simulation study of nine different metrics. Two metrics of these calculated metrics involve easily observable quantities for optical probing systems and are considered equivalent to the canonical performance test value.
NIST Interagency/Internal Report (NISTIR) - 7883
Report Number


coordinate metrology, ISO 10360, dimensional metrology, CMMs, probing


Phillips, S. (2013), Standardized Performance Testing Metrics for Optical Coordinate Measurement Systems, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 14, 2024)
Created May 9, 2013, Updated November 10, 2018