NIST researchers have developed a new generation of devices that can reduce uncertainties in ac voltage measurements by a factor of three. The improved multijunction thermal converters (MJTCs) have exceptional properties over a wide range of voltages and frequencies, allowing NIST to reevaluate its uncertainty matrix and achieve significant improvements across all voltage and frequency levels.
The new MJTCs, fabricated on fused silica substrates, have a wider useful voltage range and near-uniform AC-DC difference at frequencies from 1 MHz to 100 MHz. This allows elimination of one-third of the scaling steps. The devices are referenced to the AC Josephson voltage standard at 250 mV and will soon become the new everyday standards in NIST’s AC-DC Difference Project, offering primary standard accuracy and significantly improving the ac metrology program.
Keywords: Metrology, Uncertainty, Standards, Accuracy, Quantum
