High precision (Advanced) angle metrology: pushing the limits for nanoradian uncertainty demands

Abstract

Precise angle measuring devices – such as angle encoders, angle interferometers, small angle generators and autocollimators – are extensively used in various applications where high precision is demanded. Recently, an angle metrology project supported under European Metrology Research Programme (EMRP) has been completed. This project has made a significant contribution to traceable angle metrology targeting at nanoradian uncertainty (less than 50 nrad) for stringent demands and achieved milestones. It has provided novel methods, tools, instruments, guides and knowledge that will help to ensure use of precise angle metrology equipment for the demands which have not been answered before. Some of the new devices are already commercially available and have been started to be used for critical needs. This paper gives highlights of the project’s outputs and inform the community about recent developments in high precision advanced angle metrology.