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.

Traceability Considerations for the Characterization and Use of Measuring Systems



Charles D. Ehrlich


There are several different ways that measuring systems (which include measuring instruments) can be characterized, including calibration, adjustment, and verification (or testing). Common elements of such characterizations include comparisons of indicated values with values obtained when using measurement standards, specification of influence quantities and operating conditions, and statements of system resolution and repeatability. Differing elements of such characterizations include whether or how measurement uncertainty is recorded during the characterization, whether any change is made to the measuring system (including in hardware and software) during the characterization process, and whether recording of measured error of indication is part of the characterization process. The way that a measuring system is characterized will typically influence how measurement results are obtained and stated when subsequently using the measuring system to perform measurements. Since a measurement result includes the measurement uncertainty as well as the measured value, the metrological traceability that is ascribed to measurement results obtained when using such characterized measuring systems can be impacted by the type of characterization that was performed. Of particular note is that for some characterizations, in particular some types of verification (or testing) the measurement result might not contain an explicit measurement uncertainty, which brings the metrological traceability into question. This paper examines the different ways that measuring systems are characterized and subsequently used, and the implications for metrological traceability of associated measurement results.
NCSL International Measure


measuring systems, traceability, measurement traceability, calibration, measurement standards, repeatability


Ehrlich, C. (2016), Traceability Considerations for the Characterization and Use of Measuring Systems, NCSL International Measure, [online], (Accessed June 21, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created May 12, 2016, Updated October 4, 2019