Digital Sampling Techniques for AC Josephson Standards at NRC-Canada

The paper describes research and development (R&D) work being conducted at the NRC in the field of ac Metrology to establish a Josephson based system to provide traceability to the SI to measurements of low frequency ac quantities via digital sampling techniques. Latest achievements suggest that measurement uncertainties bearing parts in 10
⁷
or much less for frequencies up to 1 kHz are attainable. The ongoing R&D efforts also tackle challenges related to extending the application of NRC Josephson systems to frequencies towards the MHz range using special digital sampling techniques aided by custom designed instrumentation.