THE BIPM COMPACT JOSEPHSON VOLTAGE STANDARD

The BIPM has developed a new Josephson Voltage Standard (JVS) that will replace the present transportable standard in the near future. The old system has been involved in 17 international comparisons at the level of 10 V in the framework of the BIPM direct on-site JVS key comparison since 1994. The heart of the new primary standard will still consist of arrays of SIS junctions. It will be able to use future 10 V programmable arrays with minor modifications. We present here the technical details of the key parts of the compact primary JVS. The preliminary results of a direct comparison against the current BIPM 10 V primary reference have shown an agreement within a total combined relative uncertainty of 1 x 10(-10) (k = 1).