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The BIPM and NIST collaborate on the development of a new generation Kibble balance

The BIPM and NIST (USA) have started a collaboration on the development of a new generation of Kibble balance. This joint work is being carried out in response to a recommendation of the Consultative Committee for Mass and Related Quantities (CCM) for more collaboration between the different Kibble balance teams.

As part of this collaboration, NIST welcomed Dr Franck Bielsa from the BIPM Kibble balance group for five months in their team. Dr Bielsa received his Ph.D. in matter physics from the University of Paris VI in 2007. He was a Post-Doctoral Researcher with the Laboratoire National des Champs Magnétiques Intenses, Toulouse (France) in 2008. From 2009 to 2014, he was a researcher with the Laboratoire National de Métrologie et d’Essais, Paris. He joined the BIPM in 2014 where he works primarily on the Kibble balance experiment. In addition he has been a member of the CODATA task group on fundamental constants since 2021.

The main purpose of the collaboration is the further development of the Kibble balance which is part of the Quantum Electro-Mechanical Metrology Suite (QEMMS) of NIST, which can provide quantum voltage, resistance, current, mass and force dissemination directly traceable to the new SI. The aim of the new generation of small-size Kibble balances is to provide mass realization in the 10 g – 200 g range.

Dr Bielsa contributed to the development of the control software during his secondment, which allowed the characterization of the performance of the system in terms of control and led to the first velocity-phase measurement of the QEMMS with a promising signal-to-noise ratio. The main source of the measurement noise was also identified.

The software will be adapted to the operation of the compact Kibble balance system under development at the BIPM and the experience gained from the characterization of the velocity phase is expected to lead to improvement of the BIPM Kibble balance measurement.

The collaboration between the two groups will continue in the future with the aim to further extend the exchange of knowledge achieved during the secondment of Dr Bielsa to NIST.