|
|
|
| The Annealing Effect on the Performance of the Standard Platinum Resistance Thermometer |
| DENG Xiao-long1,SUN Jian-ping2,YUE Kai1,LI Jie3,WU Xin-cai3 |
1. University of Science and Technology Beijing, Beijing 100083, China;
2. National Institute of Metrology, Beijing 100029, China;
3. Hebei University, Baoding Hebei 071000, China |
|
|
|
|
Abstract Annealing is the most effective means to eliminate internal stress of SPRT that is due to factors such as mechanical vibration.At the same time, it may change the internal oxidation state of platinum wire.Four SPRTs from different countries are chosen,these SPRTs are annealed at five different temperatures (600 ℃、500 ℃、450 ℃、420 ℃、350 ℃) for 4 hours to investigate their stability at room temperature after annealing.The results show that different annealing temperature can produce different effects on resistance of thermometers,equivalent to temperature changes maximum 1 mK,the water triple point resistance changed significantly in 0 to 6 hours, to keep the platinum resistance thermometer in a same thermal state can effectively improve the temperature measurement level.
|
|
|
|
|
|
［1］Xumo L. Producing the Highest Accuracy from SPRTs［J］. Measurements & Control, 1996, 118-120.
［2］Preston-Thomas H. The International Temperature Scale of 1990 (ITS-90)［J］.Metrologia, 1990, 27: 3-10.
［3］Strouse G F. NIST implementation and realization of the ITS-90 over the range 83K to 1235K: reproducibility, stability, and uncertainties［J］.Temperature: Its Measurement and Control in Science and Industry, 1992, 6: 169-174.
［4］Nguyen M K, Ballico M J. APMP-K3: Key comparison of realizations of the ITS-90 over the range –38.8344℃ to 419.527℃ using an SPRT［J］.Metrologia, 2007, 44: Tech .Suppl.03006.
［5］Berry R J. Effect of Pt Oxidation on Pt Resistance Thermometry［J］.Metrologia, 1980,16: 117-126.
［6］Mangum B W. Summary of comparison of realizations of the ITS-90 over the range 83.8058K to 933.473K: CCT key comparison CCT-K3［J］.Metrologia, 2002,39: 179-205.
［7］Berry R J. Thermal Strain Effects in Standard Platinum Resistance Thermometers［J］.Metrologia, 1983,19: 37-47.
［8］White D R, Ballico M, Chimenti V, et al. Uncertainties in the realization of the SPRT sub range of the ITS-90［R］.CCT WG3,2009. |
|
|
|
2015, Vol. 36 
