A Proposed Interim Check for Field Testing a Laser Trackers 3-D Length Measurement Capability Using a Calibrated Scale Bar as a Reference Artifact
Vincent D. Lee, Christopher J. Blackburn, Balasubramanian Muralikrishnan, Daniel S. Sawyer, Mark Meuret, Aaron Hudlemeyer
This paper describes a proposed interim check for field testing a laser trackers 3-D length measurement capability using a calibrated scale bar as a reference artifact. The tests described here are constructed to be sensitive to uncompensated errors in length measurement caused by the imperfect geometry and optical misalignments in the laser trackers construction. The collection of tests described in this paper was specifically selected to be sensitive to all of the error sources described in the NIST, and Loser and Kyles laser tracker error models. Consequently, successful field test results obtained using the methods described here should provide operators with confidence that the instrument will perform within the required specification in the field. These tests are not a test of the trackers ranging system, which is assumed to be individually calibrated and is used to establish metrological traceability per ASME B89.7.5 of the reference lengths described in this paper. To be of practical use to laser tracker users, the tests are constructed to be quick (less than 30 minutes) and easy to perform in the field while still providing a thorough evaluation of the instruments length measurement performance. This paper describes an analytic method for selecting specific field tests, proposes a collection of field tests, and presents a method for displaying and analyzing the measurement data.