Prof Joachim Hermann Ullrich, Vice-President of the International Committee of Weights and Measures (CIPM), cum President of the Consultative Committee for Units (CCU) of the CIPM and President of the Physikalisch-Technische Bundesanstalt (PTB), the National Metrology Institute of Germany, visited the Standards and Calibration Laboratory (SCL) on July 12.

The CCU is the committee which oversees the development of the International System of Units (SI) and prepares the successive editions of the SI reference document. The most important activity of the CCU in recent years has been the preparation of a major revision of the SI, which has been referred to as the “Revised SI”. The revision, which is expected to be officially adopted in this November, includes new definitions of the kilogram, ampere, kelvin and mole, and a new way of presenting the entire system by fixing the numerical values of a set of seven “Defining Constants”.

During his visit, Prof Ullrich gave a distinguished lecture on “The Revised International System of Units (SI): New Avenues for the Realisation of the Units” to the staff of the SCL. This was followed by an in-depth technical discussion with the SCL scientists during which opportunities for further collaboration between the SCL and the PTB were explored. Prof Ullrich was then given a tour of the SCL where he was impressed by the efficiency of the SCL and what the SCL accomplishes with a limited number of staff.