Quantum Metrology for AC Voltage Measurement

In collaboration with the national metrology institute in the United States (NIST) we have established an ac voltage standard based on Josephson Junction Array Voltage Standard (JJAVS) technology, which provides us with the ability to link our ac and ac/dc difference standards and calibrations to a precisely known quantum standard.

The JJAVS is a device comprising many thousands of minute superconductor-normal material junctions connected in series. When a current is passed through such a circuit and it is irradiated with microwaves, a voltage is generated across the circuit, the value known exactly in terms of the microwave frequency. Such devices have been in common use for decades as very exact primary standards of dc voltage. Recent developments have led to the use of similar devices which provide known values of ac voltage when excited in a novel way.

NRC metrologist Dr. Peter Filipski combined his metrological and engineering capabilities to help quickly solve problems associated with the electrical leads, which were causing degradation in the accuracy and precision of the standard. After this effective sharing of know-how, the Electrical Standards Program received funding to implement a similar pulsed system in the NRC laboratory with NIST contributing the array chips for the Canadian system. NRC is now one only three NMIs worldwide providing direct traceability of ac voltage to a quantum standard.

The result of this essential work was published in a joint NRC/NIST paper at the 2008 Conference on Precision Electromagnetic Measurements and at the first Quantum AC Voltage Workshop, in Boulder, Colorado. A further publication on this topic has been published in the IEEE Transactions on Instrumentation and Measurement [1]. Dr. Filipski also took advantage of his visits to organize the first international comparison of ac/dc transfer using an ACJVS Quantum Standard.

[1] P.S. Filipski, J.R. Kinard, T.E. Lipe, Y.-H. Yang and S.P. Benz, “Correction of Systematic Errors due to the Voltage Leads in an AC Josephson Voltage Standard”, IEEE Trans. Instrum. Meas., vol.  58,  no. 4, pp 853-858, April 2009

Related Information

Institutes:

• NRC Institute for National Measurement Standards