The Josephson-Effect-Based Primary AC Power Standard at the PTB: Progress Report
ABSTRACT This paper reports the incorporation of a Josephson waveform synthesizer (JWS) into the primary standard for AC electrical power at the Physikalisch-Technische Bundesanstalt (PTB). The increase to 10 V of the amplitude delivered by the JWS has allowed matching of the levels of the signals measured to determine the active, reactive, and apparent power-at the 120-V and 5-A level, which is also measured by the device under test. The inherent noise- and drift-free voltages delivered by the JWS allow calibration of the core sampling voltmeter of the PTB primary power standard with an uncertainty of 0.4 muV/V(k = 1) in 100 signal periods and as part of the measuring sequence.
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- "An AC power standard performing a continuous calibration of the digital sampling system in every cycle of the measured signals was developed at PTB. A recently developed 10 V Josephson Waveform Synthesizer (JWS) has been incorporated into the PTB primary standard for AC electrical power . The 10 V SINIS binary arrays are used for in-situ calibration of the digital sampling voltmeter (DVM), with corrections applied over short time intervals. "
ABSTRACT: Progress in the development of a new low-frequency quantum-based AC Power Standard at the National Research Council of Canada (NRC) is described in the paper. The power standard is based on programmable Josephson voltage standard (PJVS) for providing AC voltage with quantum accuracy, and includes electronic signal generators and amplifiers, inductive voltage dividers (IVDs) and current transformers (CTs) for scaling output signals to low levels. Differential digital sampling is used for comparison of low-level output signal replicas with the PJVS output.Precision Electromagnetic Measurements (CPEM), 2010 Conference on; 07/2010
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ABSTRACT: The present PTB primary standard allows power measurements with a measurement uncertainty of about 2.5 μW / VA (k = 2). It operates at voltages up to 240 V and currents up to 10 A in the frequency range from 16 Hz up to some kHz. This paper gives a short overview of the working principle of the standard and recent improvements.MAPAN-Journal of Metrology Society of India 03/2009; 24(1):15-19. DOI:10.1007/s12647-009-0004-z · 0.79 Impact Factor
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ABSTRACT: This paper describes a sampling system designed using a commercial sigma-delta analog-to-digital converter (Sigma-Delta ADC). In addition to characterization measurements using a conventional high-quality signal generator, a Josephson waveform synthesizer that provides ultimately noise- and drift-free voltages was used. To evaluate the suitability of this sampling system as part of a transfer power standard, additional comparisons of the root-mean-square (RMS) values measured were performed against a thermal converter and the primary power sampling standard at the Physikalisch-Technische Bundesanstalt, Braunschweig, Germany. Initial analysis of the measurement data shows an effective resolution in the range of 18-19 bits at an equivalent sampling rate of 64 kHz. The integral nonlinearity error of the system was measured to be within plusmn7 muV/V or one least significant bit at this resolution.IEEE Transactions on Instrumentation and Measurement 05/2009; 58(4-58):786 - 790. DOI:10.1109/TIM.2008.2010575 · 1.79 Impact Factor