In order to improve the low-voltage calibration service at NIST we have constructed an ac Josephson voltage standard system with a maximum rms output voltage of 100 mV. Using this system we synthesized sinewaves of various audio frequencies and measured ac-dc differences on the 220 mV range of a commercial thermal transfer standard. By modifying the output resistance of the low-pass-filtered transmission-line we were able to extend our measurements frequency from a few kilohertz up to 100 kHz. Our data stand within the uncertainty budget of ac-dc difference calibrations made of this transfer standard using conventional techniques. At the conference we will present additional results using new Josephson circuits capable of reaching 200 mV.
Proceedings Title: Conference on Precision Electromagnetic Measurements Digest
Conference Dates: July 9-14, 2006
Conference Location: Torino, IT
Conference Title: Conference on Precision Electromagnetic Measurements
Pub Type: Conferences
Digital-analog conversion, Josephson arrays, Quantization, Signal synthesis, Standards, Superconductor-normal-superconductor devices, Voltage standards