The National Institute of Standards and Technology (NIST) is currently using Johnson noise thermometry (JNT) to determine the deviations of the International Temperature Scale of 1990 (ITS-90) from the thermodynamic temperature in the range of 505933 K, overlapping the ranges of both acoustic gas-based and radiation-based thermometry. Our JNT system features a quantized voltage noise source (QVNS) as a reference for the noise power spectrum. This paper describes the modifications to the system as a challenge to overcome the limitations in our previous work and furthermore enable measurements at higher temperatures. Such modifications include development of the resistance probe for higher temperatures and modifying the amplifiers. We present the results as well as the possible future improvements learnt through the measurements.
Proceedings Title: Temperature, Its Measurement and Control in Science and Industry, Volume 8
Conference Dates: March 20-May 25, 2012
Conference Location: Anaheim, CA
Conference Title: 9th International Temperature Symposium
Pub Type: Conferences
Johnson Noise, Noise Thermometry, Josephson Effect, Quantized Voltage