| Title | Improvements in the NIST Johnson noise thermometry system |
| Publication Type | Journal Article |
| Year of Publication | 2009 |
| Authors | Benz, S.P., Qu J., Rogalla H., White D.R., Dresselhaus P.D., Tew W.L., and Nam S.W. |
| Journal | IEEE Transactions on Instrumentation and Measurement |
| Volume | 58 |
| Issue | 4 |
| Pagination | 884 - 890 |
| Date Published | 2009 |
| ISSN | 00189456 (ISSN) |
| Keywords | Acoustic noise measurement, Boltzmann equation, Boltzmann's equation, Control nonlinearities, Correlation, Digital-analog conversion, Frequency response, Josephson arrays, Measurement units, Measurements, Noise measurement, Quantization, Signal synthesis, Synthesis (chemical), Systematic errors, Temperature measurement, Temperature sensors, Thermometers, Uncertainty analysis, Units of measurement |
| Abstract | We have developed a Johnson noise thermometry (JNT) system that is calibrated by precision waveforms synthesized with a quantized voltage noise source (QVNS). Improvements to the QVNS and the cross-correlation measurement electronics have significantly reduced systematic errors and measurement uncertainty. We describe in detail a number of these improvements, such as amplifier performance and frequency response. We also show details of recent measurements that characterize the nonlinearities and distortion properties of the measurement electronics. Finally, we present an uncertainty analysis and discuss the potential for the QVNS-JNT technique to contribute to the redefinition of Boltzmann's constant. © 2008 IEEE. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-63449141908&partnerID=40&md5=8833e5dd631474ac8c8923f7818ef9c9 |
| DOI | 10.1109/TIM.2008.2007027 |
