AC-DC Difference
DC Voltage

Latest News:

• We recently completed a DC voltage intercomparison with the Bureau International des Poids et Mesures (BIPM). Two Josephson Voltage Standards were intercompared over the course of a week, using several different protocols. The agreement between the two systems was excellent:-0.1 nV at 10 V, with an uncertainty of 1.08 nV. This result solidifies NIST as a world-class metrology institute, and will allow us to play a much more active role in international metrology, particularly in North and South America.
  
• We are continuing to develop multijunction thermal converters for applications at frequencies up to 100 MHz and for currents up to 1 A. Our new current converters show very good performance from 10 Hz to 100 kHz. For more information about MJTC development, click here.
• We have improved the output transmission line for our quantum AC standard to the point where it makes a negligible contribution to the uncertainty of the system out to 1 MHz. We plan to report our work on the ACJVS out to 1 MHz soon. For more information about MJTC development, click here.
• Work to support current shunt calibrations for the US Air Force has enabled us to reduce our uncertainties for high current (100 A) shunts at 100 kHz to below 200 µA/A, as a Special Test. For more information, contact us.