The objective of the project was to develop a simple and robust measurement device for angle measurements up to 10 degrees with uncertainty below 1".
The device is terminated. It consists of two rotary tables of high accuracy and autocollimators. It can be used to calibrate gauge blocks, autocollimators and angular laser interferometers. It can achieve an uncertainty of 0.2" (one sigma) (Publication EUR Report 11762).
It was then circulated to a number of laboratories for an intercomparison to determine its performance when measuring angle gauge blocks in the range of 1" to 30". The device itself was calibrated by each participant using 5 transfer standards of nominally 1", 2", 5", 20" and 30". This calibrated instrument was then used by each participant to measure a similar set of gauges of unknown value. It was shown that the spread of the results (1 sigma) was within 0.02" and 0.07" if two outliers were not considered.
In addition, three of the participating laboratories measured the five transfer standards using their own calibration facilities. The spread of the results (1 sigma) was within 0.03" and 0.05". It was shown that the actual angle of one of the transfer standards was clearly outside the range certified by its manufacturer.
Detailed results were published in EUR Report 14058.