Since joining NPL in 1976, Ian Robinson has worked on dc and low-frequency measurements of resistance and voltage. Ian is now an NPL Fellow in Electrical Metrology and has made major contributions to many key milestones in this area.
Ian worked on the first moving-coil watt balance, now known as the Kibble Balance, which played a key part in determining a worldwide consensus value for the maintained volt (ampere) in 1990.
The discovery and development of the Quantum Hall Effect in the 1980s allowed the Kibble Balance to measure mass in terms of fundamental constants. Ian worked with Bryan Kibble on an in-vacuum balance – the NPL Mk II. Producing a working Kibble balance was once compared by Nature to the difficulty of the search for the Higgs Boson. However, all the significant problems involved with this apparatus were solved at NPL by 2009.
In 2017 the NPL Mk II balance, operating at NRC in Canada, contributed the lowest uncertainty results for the value of the Planck constant in terms of the existing value of the SI kilogram. This led directly to the 2019 redefinition of the kilogram in terms of a fixed numerical value of the Planck constant - the principal constant underpinning Quantum Physics.
In the early part of the last decade, Ian added to the theory of the technique. This new theory suggested ways to simplify the construction and operation of the balance and has seen success in other laboratories around the world. Ian is now leading a team to realise the new ideas and produce a simplified, but accurate, instrument which will allow many countries around the world to make fully independent measurements of mass using the new definition of the kilogram.
Ian and the team hope that this will foster further collaboration between such countries to ensure that the world has a mass scale which is unified, accurate and stable. The technique is not limited to masses in the kilogram range and Ian is supervising work to extend the technique to measure smaller masses.
Ian has also made major contributions to the scientific community having published or presented over 50 papers and articles. He also chaired the Consultative Committee for Electricity and Magnetism working group on electrical methods to monitor the stability of the kilogram, the work of which was completed by the redefinition.
Ian Robinson states: "I was surprised and extremely honoured to receive the award. It is wonderful to know that the work that I have been doing for a long time has been recognised in this way. It is also a great accolade for the team that is working with me, showing that efforts in this, somewhat specialised, area are appreciated by the UK. The pandemic has been a tough period for the whole country and my family and myself are no exceptions. There were some highlights for us during the period: the birth of my third granddaughter and my son, Alex, appearing on "Grayson's Art Club". This honour is certainly an exceptional highlight for us and, hopefully, comes at a time when circumstances are improving for everyone in the UK."
12 Jun 2021