A length measurement is said to be traceable if it can be traced back to the unit metre, which in turn is defined by the speed of light in vacuum c and the unit second: "The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second".
A Nanometre (nm) is the 1 / billion (10-9) part of a metre. Sub-nm means even smaller than 1 nm. The need for improved accuracy in this range is strictly required for certain applications in metrology and industry.
This EMRP project comprising six funded, one unfunded National Metrology Institute (NMI) partners together with two more JRP-participants from universities is coordinated by PTB (Germany). The project aims to improve the traceability of laser interferometers and capacitive sensors, which are the most widely used measurement devices to measure lengths or displacements with utmost precision and accuracy today.
With in this project, a detailed set of comparison measurements between the x-ray interferometer (NPL, UK) and the (differential) Fabry-Perot interferometer (TÜBİTAK UME) will be made. Quadrature and/or sub-quadrature x-ray fringe displacement measurements will be performed to demonstrate the capabilities of of both instruments for picometre displacement metrology.
TÜBİTAK UME will also take part in the work for the referencing, characterisation and calibration of capacitive sensors. Sub-nm displacement measurements for capacitive sensors for an extended measurement range are targeted.
For a more detailed information about the project, please click on the following link: http://www.ptb.de/emrp/882.html.
(Completed)