NIST has developed the world’s first precision instrument for directly measuring AC voltages using Josephson junction technology. This new standard could significantly improve measurement accuracy for industrial voltmeters, spectrum analyzers, amplifiers and filters, particularly at low voltages (2 millivolts) where it could improve accuracy by 1,000 times.
The instrument uses arrays of Josephson junctions to generate AC pulses in precisely measured voltage units over a range of audio frequencies. NIST researchers have developed “nano-stacked” arrays of junctions to increase output voltage, with programmable voltage standard integrated circuits containing over 130,000 junctions on a single chip.
The new AC voltage standard could establish an entirely new method for AC voltage metrology, replacing the current indirect method of measuring heat delivered by an instrument to a resistor. NIST researchers hope to eventually increase the instrument’s maximum output from 100 millivolts to 1 volt.
Source: https://www.nist.gov/news-events/news/2006/07/road-ac-voltage-standard-leads-important-junction
Keywords: Josephson junction, Quantum physics, AC voltage metrology, Standard integrated circuits, Nano-stacked arrays
