Determination of Laser Tracker Angle Encoder Errors
National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom
a Corresponding author: firstname.lastname@example.org
Published online: 19 August 2014
Errors in the angle encoders of a laser tracker may potentially produce large errors in long range coordinate measurements. To determine the azimuth angle encoder errors and verify their values stored in the tracker’s internal error map, several methodologies were evaluated, differing in complexity, measurement time and the need for specialised measuring equipment. These methodologies are: an artefact-based technique developed by NIST; a multi-target network technique developed by NPL; and the classical precision angular indexing table technique. It is shown that the three methodologies agree within their respective measurement uncertainties and that the NPL technique has the advantages of a short measurement time and no reliance on specialised measurement equipment or artefacts.
© Owned by the authors, published by EDP Sciences, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.