National Physical Laboratory

Laser Trackers

Laser Trackers

Laser trackers are polar coordinate measuring systems capable of high accuracy measurements over long distances, for example the system used by NPL can measure 40 m distances to within ± 60  μm.

The tracker makes measurements of the positions of spherically mounted retro-reflectors (SMRs) in terms of two angles (horizontal and vertical), measured using angular scales mounted in the tracker mechanics, and distance (radius) to the SMR, using a laser interferometer. Simple trigonometry converts these into the usual Cartesian coordinates people are used to dealing with (x, y, z). Special tooling fixtures allow the measurement of not just individual point locations, but also of surfaces (flatness, level), angles (squareness), surface form and alignment between parts. By combining laser trackers with other measuring systems, such as laser scanners, large objects with complex surfaces can be measured.

Click here for further information on NPL's large scale metrology capabilities


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Last Updated: 31 Jul 2017
Created: 17 Jan 2011


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