NIST logo

Ranging Tests for Laser Trackers

Ranging system test of a laser tracker.

Ranging system test of a laser tracker.

The Dimensional Metrology Group (683.01) provides high accuracy calibrations of laser tracker ranging systems and similar instruments. The test is performed by comparing the observed laser tracker ranging system displacement of a retroreflector to that measured by a frequency-stabilized helium neon laser interferometer traceable to the SI meter.

The Dimensional Metrology Group facility consists of an underground tunnel having 0.2 °C temperature control, with a measuring bench 61 meters (200 feet) in length. Additionally, precision temperature (0.01 °C), pressure and humidity corrections are applied to the laser wavelength over the beam line. The ranging system tests can be performed as described in the American Society of Mechanical Engineers (ASME) B89.4.19-2006 laser tracker performance evaluation Standard. Each calibration includes a NIST calibration report that provides the measured error and uncertainty for each displacement length.


The expanded uncertainty U in the measured error with k = 2 is U (k = 2) = (5 + 0.3L) µm where L is the length of the displacement in meters.

Other Special Tests in the Dimensional Metrology Group >>

Bookmark and Share


Physical Measurement Laboratory (PML)
Engineering Physics Division

Dimensional Metrology Group (683.01)
Daniel S. Sawyer, Calibration Coordinator
301-975-5863 Telephone

General Information:
James R. Bowie, Secretary
301-975-3468 Telephone
301-975-5360 Facsimile

100 Bureau Drive, M/S 8211
Gaithersburg, Maryland 20899-8211