At its meeting in 1996 the CCT initiated five Key Comparisons to test the equivalence of realisations of the ITS-90 between National Measurement Institutes. CCT-K1 covers the temperature range from 0.65 K to 24.5561 K, in which the ITS-90 is defined by specified vapour-pressure equations for 3He (0.65 K to 3.2 K) and 4He (1.25 K to 5.0 K) and interpolation equations for a constant-volume gas thermometer (ICVGT) using 3He or 4He (3 K to 24.5561 K). The comparison was carried out using rhodium-iron resistance thermometers from the seven participating laboratories represented by the authors. The measurements were made in two experiments at NPL, which also coordinated the comparison.
Proceedings Title: TEMPMEKO 2004: 9th International Symposium on Temperature and Thermal Measurements in Industry and Science
Conference Dates: June 22-25, 2004
Conference Location: Cavtat - Dubrovnik , -1
Pub Type: Conferences
gas thermometry, helium vapor pressures, ITS-90, key comparison, resistance thermometry, temperature scales, thermometry