Accuracy is important to every organisation, let alone one that is principally concerned with standards of measurement.
Indeed, for the National Physical Laboratory (NPL) based in South West London, ensuring the best possible accuracy is crucial to eliminating uncertainty – a vital aspect of its ongoing work.
Established in 1900, NPL is the UK’s national metrology institute and is central to the development and maintenance of national primary measurement standards. It is a public corporation owned by the Department of Business, Energy, and Industrial Strategy (BEIS), and has partnering agreements with the University of Strathclyde and the University of Surrey.
NPL operates in an all-encompassing position between academia, research and industry; and the impact of its work can be felt across the whole of society. As its own website points out, accurate, standardised measurement allows for everything from the correct administration of medicine to the production of materials with desired qualities. In short, its work underpins much of the UK’s prosperity and quality of life.
Designing and manufacturing measurement equipment is a significant part of NPL’s remit. In 2016, funds were earmarked to update and develop the existing engineering workshop to support the laboratory’s in-house production of world-class measurement instruments used in standardisation and research projects in both the UK and around the world.
The decision to expand manufacturing capacity underlined the need for new equipment. In this field of research, however, where even the smallest margins of error can jeopardise an entire project, only the most precise machine tools were considered.
“Development of the new facility meant a number of older assets needed replacing,” says Geoff Stammers, NPL’s head of engineering services. “Following a competitive tender process, Yamazaki Mazak stood out and was chosen as our preferred supplier.”
He continues: “It helped that Mazak had a UK base in Worcester, could provide a high level of support, and were willing to work with NPL’s engineers to help develop and train our apprentices. We were keen to see every pound spent generate a lasting return, so this kind of assurance is invaluable.”
Alan Mucklow, managing director UK & Ireland sales division at Yamazaki Mazak, adds: “NPL is globally renowned for working at the cutting edge of measurement science. To be able to supply machine tools into such an establishment is certainly a real landmark installation for Mazak in the UK. Ultimately, there is no greater endorsement for the accuracy and repeatability of our machines than for them to be used by one of the world’s premier authorities on metrology instrumentation.”
Following the tender process, NPL took delivery of four Mazak machines: the VTC-800/20SR vertical travelling column 5-axis machining centre, a Quick Turn 250MY turning centre, and a VCN-530C and VCN-430A from Mazak’s portfolio of vertical machining centres.
Unsurprisingly, it was the Mazak equipment’s ability to repeatedly manufacture parts to high tolerances, which proved favourable with engineers. Mr Stammers continues: “While we’re looking to be as efficient as possible, quality will always be our first concern. Legitimate scientific research depends on precise instruments that can be used repeatedly, reliably and to the same result. This principle applies to both the equipment we use and the parts we produce.
“Additionally, Mazak’s machines have increased efficiencies at NPL. The fact we can use the equipment safe in the knowledge that quality will not be compromised, is very important.”
Notable work has included using the Quick Turn 250MY to produce parts for prototype Kibble balances – an electromechanical device designed at NPL that generates an extremely accurate measurement of mass based on quantum electrical standards.
These prototypes are part of a larger research project to produce a new design of the Kibble balance after the definition of the kilogram was changed in 2019. Specifically, it changed from the mass of a physical weight kept at the International Bureau of Standards in Paris, to a definition based on the Planck constant – a fundamental constant of nature.
The new Kibble balance will be used in both the UK and national metrology institutes around the world to realise the new kilogram definition.
NPL is also a world-leader in acoustic gas thermometry, and the instruments it has produced have made some of the most accurate temperature measurements in history, which are important for the manufacture of aero-engines as well as measuring the effects climate change.
Key components in these instruments were made using Mazak machine tools – the Quick Turn 250MY and VTC-800/20SR. Mazak machine tools were also used to make specialised mechanical parts for mobile differential absorption LIDARs (DIAL). The NPL DIAL is a laser-based remote sensing technology that is able to remotely map and quantify Green House Gases (GHGs) and pollutant emissions in the atmosphere.
National Physical Laboratory (NPL)