1. College of Metrology & Measurement Engineering,China Jiliang University, Zhejiang Hangzhou 310018, China
2. National Institute of Metrology, Beijing 100029, China
Abstract:Application of fixed point thermometry technology to the field calibration of shipbrone sensors is a key strategy for achieving flattening in temperature measurements and enhancing the accuracy of oceanic temperature measurements. The fixed points defined by ITS90 in the temperature from -5℃ to 35℃ is inadequate, which blocks the accuracy improvement of the marine NTC thermistors. A new miniature Ga-In eutectic fixed point was developed, and the reproducibilities of the fixed point in temperature controlled box and ambient environment were investigated. Two methods including the tangent intersection method and cubic polynomial fitting were used to obtain the values of the temperature plateaus. The results showed that the reproducibility of the miniature Ga-In eutectic fixed point is better than 1mK. In order to obtain better performance, the miniature Ga-In eutectic fixed point should be kept in solid state at temperature below its melting point. Using the tangent intersection method, the phase transition temperature of the miniature Ga-In eutectic fixed point is determined to be 15.6549℃,with an expanded uncertainty of 1.54mK(k=2).
WANG A J, ZHAO Z Y, ZHANG C, et al. The Stability Evaluation of Marine Environmental Parameter Monitoring Sensors[J]. Ocean Development and Management. 2022, 39(12): 115-120.
GAO Z K, YUAN L L, JIANG F. Analysis of Results about the Comparison of Marine Temperature Calibration[J]. Acta Metrologica Sinica. 2022, 43(2): 268-273.
ALLAN R P, HAWKINS E, BELLOUIN N, et al. Summary For Policymakers[R]. IPCC(2021),2021.
WANG J C, SUN J C, LIU Y, et al. Research Progress and Prospect of Marine Monitoring Instruments and Equipment in China [J]. Strategic Study of CAE, 2023, 25(3): 42-52.
Ren Q, Yu F, Wei C J, et al. Comparison and Analysis on Conductivity-Temperature-Depth System (CTD) Data Quality[J]. Studia Marina Sinica, 2016(1): 288-295.
WU X F, ZHOU H, CAO M J, et al. Preliminary Quality Discussion Between Ship-Based CTD and Profiling Floats Observational Data[J]. Oceanologia Et Limnologia Sinica. 2019, 50(2): 278-290.
REN G X, WANG X Y, DU L B. Design of High-precision and Fast-response Temperature Measurement System for Ocean[J]. Instrument Technique and Sensor, 2011(2): 45-47.
WANG B Y, ZENG F C, FU C Y, et al. Study on In-situ Calibration of Precision Platinum Resistance Thermometer Based on Micro Gallium Fixed-point[J]. Acta Metrologica Sinica. 2022, 43(2): 210-214.
ZENG J X, PAN J, SUN J P, et al. Development of Miniature Double Temperature Fixed Point Cell[J]. Acta Metrologica Sinica, 2021, 42(4): 458-462.
SUN J P, ZENG F C, ZHANG L, et al. Onsite Calibration of the Precision Industrial Platinum Resistance Thermometer Based on Gallium and Gallium-based Small-size Eutectic Points[J]. Acta Metrologica Sinica, 2015, 36(z1): 32-36.
BURDAKIN A, KHLEVNOY B, SAMOYLOV M, et al. Development of gallium and gallium-based small-size eutectic melting fixed points for calibration procedures on autonomous platforms[J]. International Journal of Thermophysics, 2009, 30: 20-35.
RUAN Y M, LING Z Q, LI T, et al. Exploration of Bi-In-Sn Alloy Melting Temperature Plateau Optimization[J]. Acta Metrologica Sinica. 2022, 43(2): 176-183.
YANG L, BIAN X F, PAN S P, et al. Cluster separation phenomena in liquid Ga-In alloys[J]. Acta Physica Sinica, 2012, 61(3): 314-321.
[11]
BURDAKIN A, KHLEVNOY B, SAMOYLOV M, et al. Melting points of gallium and of binary eutectics with gallium realized in small cells[J]. Metrologia, 2008, 45(1): 75.
LI T, SUN J, WANG H, et al. Development and precise determination of high reproducibility Ga-In eutectic temperature fixed point[J]. Journal of Alloys and Compounds, 2022, 903: 163781
[18]
KRAPF G, SCHALLES M, FR?HLICH T. Estimation of fixed-point temperatures — A practical approach[J]. Measurement, 2011, 44(2): 385-390.
YANG Y, CHEN L, SUN J P, et al. Study on the Development and Reproducibility of Bromobenzene Melting Point[J]. Acta Metrologica Sinica, 2022, 43(2): 157-162.
WEN P, HAO X P, SUN J P, et al. On-orbit Calibration of Temperature Sensor Based on Miniature Gallium-based Alloy Fixed Point[J]. Acta Metrologica Sinica. 2019, 40(4): 595-602.
SUN J P, QIU P, ZHANG J T. The Evaluation of the Influence of lmpurities on the Freezing Point of Zinc [J]. Acta Metrologica Sinica., 2010, 31(3): 223-228.