Fang H.,Bureau International des Poids EtMesures |
Kiss A.,Bureau International des Poids EtMesures |
De Mirandes E.,Bureau International des Poids EtMesures |
Lan J.,Tsinghua University |
And 5 more authors.
IEEE Transactions on Instrumentation and Measurement | Year: 2013
This paper presents the progress made to improve and develop the Bureau International des Poids et Mesures (BIPM) watt balance during the last two years. A reduction by a factor of five of the type A uncertainty was achieved by refining the velocity measurement. The BIPM simultaneous weighing and moving approach was experimentally compared to a bifilar coil technique. The relative difference to the Planck constant determination between the two approaches is 2 × 10-7 with a type A uncertainty of 3 × 10-7. A vacuum enclosure located in a dedicated laboratory with better thermal and vibrational isolation is ready to receive the present apparatus for further improvement. © 1963-2012 IEEE.