Bilateral Comparison of Mercury and Gallium Fixed-Point Cells Using Standard Platinum Resistance Thermometer

作者：Bojkovski J^*; Veliki T; Zvizdic D; Drnovsek J

来源：International Journal of Thermophysics, 2011, 32(7-8): 1544-1552.

DOI：10.1007/s10765-011-1035-6

• Interlaboratory comparison
• Melting point of gallium
• Standard platinum resistance thermometer (SPRT)
• Triple point of mercury
• W value

The objective of project EURAMET 1127 (Bilateral comparison of triple point of mercury and melting point of gallium) in the field of thermometry is to compare realization of a triple point of mercury (-38.8344 A degrees C) and melting point of gallium (29.7646 A degrees C) between the Slovenian national laboratory MIRS/UL-FE/LMK and the Croatian national laboratory HMI/FSB-LPM using a long-stem 25 Omega standard platinum resistance thermometer (SPRT). MIRS/UL/FE-LMK participated in a number of intercomparisons on the level of EURAMET. On the other hand, the HMI/LPM-FSB laboratory recently acquired new fixed-point cells which had to be evaluated in the process of intercomparisons. A quartz-sheathed SPRT has been selected and calibrated at HMI/LPM-FSB at the triple point of mercury, the melting point of gallium, and the water triple point. A second set of measurements was made at MIRS/UL/FE-LMK. After its return, the SPRT was again recalibrated at HMI/LPM-FSB. In the comparison, the W value of the SPRT has been used. Results of the bilateral intercomparison confirmed that the new gallium cell of the HMI/LPM-FSB has a value that is within uncertainty limits of both laboratories that participated in the exercise, while the mercury cell experienced problems. After further research, a small leakage in the mercury fixed-point cell has been found.

• 出版日期2011-8