In 2010 NIST measured the Boltzmann constant k by use of an electronic technique that measured the Johnson noise of a 100 Ohm resistor at the triple point of water (TPW). The NIST Johnson noise thermometry (JNT) system used as a reference a voltage waveform that was synthesized with a quantum voltage noise source (QVNS) that consisted of pulse-driven arrays of Josephson-junctions. In this paper, we attempt to reproduce the previous measurement of k by repeating the JNT measurement with a 200 Ohm sense resistor and appropriately modified QVNS circuit and waveform. Preliminary results show agreement with the previous value within the measurement uncertainty.
Proceedings Title: Conference on Precision Electromagnetic Measurements Conference Digest
Conference Dates: July 1-6, 2012
Conference Location: National Harbor, MD
Conference Title: Conference on Precision Electromagnetic Measurements
Pub Type: Conferences
Boltzmann equation, Correlation, Digital-analog conversion, Josephson arrays, Measurement units, Noise Measurement, Quantization, Signal synthesis, Standards, Temperature.