A high-resolution distance meter was fabricated using optical waveguide modulators. An optical intensity modulation frequency of 28 GHz was utilized for the displacement measurement when the driving frequencies to the optical modulators were around 14 GHz. The distance meter was evaluated in the National Research Laboratory of Metrology (NRLM) tunnel, which is a semi-underground tunnel. The measurement resolution is 1 and 3 µm for a distance of 5 and 100 m, respectively, in one standard deviation after correction of the cyclic error. Furthermore, cyclic errors are examined for 28 GHz optical intensity modulation.

The results of the APMP key comparison on calibration of gauge blocks by interferometry (APMP.L-K1) are reported. The comparison involved the measurement, by ten participating institutes, of eight steel gauge blocks and ten ceramic gauge blocks ranging from 0.5 mm to 100 mm in length using techniques based on interferometry. The results are analysed using En values with weighted mean values as the reference values. Some measurement results had to be excluded by application of the En-criterion for the steel and ceramic gauges. Investigations of the reasons for the deviations have already been started by the respective institutes, including follow-up gauge block comparison, APMP.L-K1.1 with the same pilot laboratory as APMP.L-K1.Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

No abstract

No abstract

No abstract