Low-Frequency Characterization in Thermal Converters Using AC-Programmable Josephson Voltage Standard System

Abstract

We have measured the low-frequency characteristics of thermal voltage converters down to 1 Hz using a differential sampling measurement system based on ac-programmable Josephson voltage standard (AC-PJVS) system. The measured ac-dc transfer difference of a planar multijunction thermal converter using our system is evaluated to be < 1 μV/V above 10 Hz and < 35μV/V at 1 Hz with lower uncertainties compared to the conventional method. The estimated overall uncertainty measured by using our system is 3.1 μV/V (k = 1) at the frequency of 10 Hz and root-mean-square voltage of 3 V. Our measurement results above 10 Hz are in good agreement with the results obtained by the conventional method within a standard deviation of the mean. Our differential sampling measurement system using AC-PJVS is a useful tool for low-frequency ac voltage metrology.

Extending voltage range to 10 V rms in AC–DC difference measurements with AC programmable Josephson voltage standard

“…The Fluke 5720A commercial calibrator was used as the AC source for a frequency range above 10 Hz and the DC source, and Fluke 5520A was used Schematic of the measurement setup for evaluating the TVC based on the AC-PJVS system (highlighted in grey) using the larger-scale PJVS chip that allows for outputs at an rms value of 10 V. The sampling digital voltmeter (DVM) highlighted in grey was modified to be locked with an external 20 MHz clock signal via an optical isolator, unlike our previous setup for the AC-DC difference measurement at 3 V © 2013 IEEE. Reprinted, with permission, from [24].…”

“…Previously, a differential sampling measurement system capable of producing an rms amplitude of 3 V and performing TVC measurements was developed using the AC-PJVS for low-frequency applications down to 1 Hz [24]. The goal of our study is to eventually replace the conventional system by the differential sampling system based on the AC-PJVS for reduced uncertainties.…”

Fabrication of Thin Film Multijunction Thermal Converters With Improved Long-Term Stability

“…The development of thermal converters has been one of the main interests in research on ac-dc transfer standards. Meanwhile, numerous studies of ac voltage standards based on quantum effects have been intensively conducted recently [10]- [15]. Among these, a method of using a thermal converter in combination with an ac Josephson voltage standard has been proposed to achieve the highest attainable accuracy [14], [15].…”

“…Meanwhile, numerous studies of ac voltage standards based on quantum effects have been intensively conducted recently [10]- [15]. Among these, a method of using a thermal converter in combination with an ac Josephson voltage standard has been proposed to achieve the highest attainable accuracy [14], [15]. It is highly possible that thermal converters will continue to be used to extend the voltage and frequency range of ac voltage standards even if quantum-based ac standards are realized.…”

Generation of 10 Vrms waveforms using AC-programmable Josephson voltage standard system with 10 K cooler

“…In these experiments, a Josephson junction array (JJA) composed of 65 536 NbN-based junctions, which can generate AC voltage of about 3 Vrms, was used, and we successfully evaluated the low-frequency characteristics below 10 Hz of a thermalvoltage converter (TVC) with an uncertainty level of 1.3 μV/V (k = 1) [8]. To enhance the usefulness of our system toward practical applications, however, the output amplitude of 3 Vrms would not enough in some measurements for TVC, etc.…”