Precision square waves synthesized by programmable Josephson voltage standards for induced voltage compensation in a Joule balance

Wang, Gang; Zhang, Zhonghua; Lu, Yunfeng; Xu, Jinxin; Zhou, Kunli

doi:10.1088/0957-0233/27/1/015003

Cited by 7 publications

(7 citation statements)

References 37 publications

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“…A programmable Josephson voltage reference does not produce well defined transitions between voltages ( section 3.3.2 ) and this can increase the uncertainty of the measurement. This problem is solvable and is presently under investigation [ 63 , 64 ].…”

Section: Design and Operation Of Kibble Balancesmentioning

confidence: 99%

The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass

2016

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The redefinition of the SI unit of mass in terms of a fixed value of the Planck constant has been made possible by the Kibble balance, previously known as the watt balance. Once the new definition has been adopted, the Kibble balance technique will permit the realisation of the mass unit over a range from milligrams to kilograms. We describe the theory underlying the Kibble balance and practical techniques required to construct such an instrument to relate a macroscopic physical mass to the Planck constant with an uncertainty, which is achievable at present, in the region of 2 parts in 10 8 . A number of Kibble balances have either been built or are under construction and we compare the principal features of these balances.

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Section: Design and Operation Of Kibble Balancesmentioning

confidence: 99%

The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass

2016

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“…As the rise and fall transitions between quantized voltages is with the time range of 2-3 µs [11], the sampling interval of the digitizer PXI 5922 is set to 0.2 µs (5 MHz) to avoid the aliasing effect. To accurately acquire the waveforms, the gain error of the PXI 5922 with 5 MHz sampling rate is characterized by directly measuring the output voltage of the PJVS.…”

Section: Gain Error Of the Digitizermentioning

confidence: 99%

Stepwise compensation waveform generation by using Josephson voltage standards for joule balance

Wang

You

et al. 2016

Meas. Sci. Technol.

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Flux linkage difference in the new joule balance can be obtained by the time integration of the induced voltage u(t) from the suspended coil relative to a moving magnet driven by a dc motor translation platform. Due to the finite acceleration of the dc motor, the transition and waveform of u(t) are finite and not regular. To accurately measure the time integration of u(t), a compensation waveform with precision time integration should be synthesized. In this paper, a stepwise compensation waveform is synthesized by a programmable Josephson voltage standard (PJVS) according to u(t). The accuracy of measuring the stepwise waveform with multiple transitions can be improved by reducing the ratio of the time integrated value of the total transitions to the total waveform less than one part in 102 in the joule balance. The time integration of the rise/fall transition is measured by a synchronized reference square wave generated by another PJVS system. With the total time integration more than 20 Vs, the uncertainty of the generated stepwise waveform is within 5.2 × 10−8 VsV−1s−1. The result confirms that the PJVS has the capability to generate a stepwise compensation voltage for flux linkage difference measurement.

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“…The commercial PJVS system from the National Institute of Standards and Technology (NIST) has been built for the joule balance experiment since 2013. The rise/fall voltage of the waveform generated by the PJVS is not known and varies with the system parameters [4,5], but the time integration of the waveform is predictable and the PJVS has the capability to generate precision voltage waveforms for the joule balance [6].…”

Section: Measurement Science and Technologymentioning

confidence: 99%

“…Thus, the digitizer PXI 5922 is calibrated in advance and used to acquire only the rise/fall transitions of the compensation waveform generated by the PJVS. The steady state value of the waveform is exactly the voltage returned from the PJVS system after the waveform command is executed [6]. The schematic used to acquire the transitions is shown in figure 1(b).…”

Section: Measurement Setupmentioning

confidence: 99%

Uncertainty estimation of non-ideal analog switches using programmable Josephson voltage standards for mutual inductance measurement in the joule balance

Wang

Zhang

et al. 2016

Meas. Sci. Technol.

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Measurement of the mutual inductance is one of the key techniques in the joule balance to determine the Planck constant h, where a standard-square-wave compensation method was proposed to accurately measure the dc value of the mutual inductance. With this method, analog switches are used to compose an analog-switch signal generator to synthesize the excitation and compensation voltages. However, the accuracy of the compensation voltage is influenced by the non-ideal behaviors of analog-switches. In this paper, the effect from these non-ideal switches is analyzed in detail and evaluated with the equivalent circuits. A programmable Josephson voltage standard (PJVS) is used to generate a reference compensation voltage to measure the time integration of the voltage waveform generated by the analog-switch signal generator. Moreover, the effect is also evaluated experimentally by comparing the difference between the mutual inductance measured with the analog-switch signal generator and the value determined by the PJVS-analog-switch generator alternately in the same mutual inductance measurement system. The result shows that the impact of analog switches is 1.97 × 10 −7 with an uncertainty of 1.83 × 10 −7 (k = 1) and confirms that the analog switch method can be used regularly instead of the PJVS in the mutual inductance measurement for the joule balance experiment.

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Precision square waves synthesized by programmable Josephson voltage standards for induced voltage compensation in a Joule balance

Cited by 7 publications

References 37 publications

The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass

The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass

Stepwise compensation waveform generation by using Josephson voltage standards for joule balance

Uncertainty estimation of non-ideal analog switches using programmable Josephson voltage standards for mutual inductance measurement in the joule balance

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