Feb 10 2015
Abu Dhabi Quality and Conformity Council (QCC), in the United Arab Emirates, has purchased a Gauge Block Interferometer designed by the National Physical Laboratory (NPL) and manufactured under licence by Hexagon Metrology UK
Staff from Hexagon hand over the interferometer to staff at QCC in Abu Dhabi (photo courtesy of Hexagon Metrology)
Gauge blocks are one of the most popular length standards in use throughout the world, providing traceability to the SI metre. The NPL-designed Gauge Block Interferometers, sold commercially through Hexagon Metrology, are used worldwide for the highest accuracy calibration of gauge blocks and similar engineering artefact standards.
QCC is an Abu Dhabi government entity, established to ensure the provision of quality infrastructure in line with global standards. Staff from Abu Dhabi travelled to Hexagon Metrology in Telford to view the instrument prior to shipping and receive several days of hands-on training given by Andrew Lewis from NPL's Engineering Measurement Division.
The NPL Gauge Block Interferometer was designed and licensed to Hexagon Metrology nearly 30 years ago and several iterations and variations of the basic design have been produced. The latest version of the instrument uses a phase-stepping technique to measure the surface topography of the gauge block, as well as a dual laser system to determine the absolute length. Uncertainties of around 20 nm to 30 nm can be achieved on gauge blocks up to 100 mm in length.
The C++ instrument control software, developed at NPL by Ben Hughes and Andrew Lewis, is also sold through Hexagon, and stabilised lasers used in the interferometers are manufactured by Hexagon under NPL licence. Instruments and lasers based on NPL designs have been sold to 27 different countries worldwide, with typical customers including NMIs, accredited laboratories and high technology laboratories and organisations.