NIST provides special tests for measurements on length standards using coordinate measuring machines (CMM). This is the service of choice for length artifact configurations like 1-D ball bars, 1-D conical seat gauges, line scales, stage micrometers or any other type of unusual 1-D length gauge (excluding step gauges, which have a unique SP250 Service ID number, 11060S) of standard or non-traditional materials. The measurement methods, defined measurands, and fixturing considerations are researched and modified for the specific client or artifact use requirements.

Depending on the artifact and the needs of the client, a suitable CMM and measurement method will be selected. For the most demanding measurements of high-quality artifacts, the uncertainty will generally follow the formula where the expanded uncertainty U (k=2) ~ 100 + 200*L nanometers (where L is the length of the artifact in meters). For example, a 1.0 meter artifact would have an expanded uncertainty (k=2) of approx. 300 nanometers.

Inquiries on the specific measurement methods and procedures should be directed to the technical contact.