Article
Engineering, Multidisciplinary
Yoshiro Yamada
Summary: The investigation into the cause of furnace effect during the realization of high-temperature fixed points at the copper point showed that modifications of the cavity design and applying a small aperture at the cavity opening can reduce the effect. It was found that the interaction between the furnace and the cavity through reflection at the cavity side wall is linked to the design of the HTFP cells, and the effect at the copper point in a HTFP furnace is estimated to be around 14 mK or less, causing the realized temperature to be lower than the true temperature.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Multidisciplinary
H. C. McEvoy, D. H. Lowe, R. Underwood, M. de Podesta, G. Machin, M. J. Martin, J. M. Mantilla, J. Campos, M. Sadli, F. Bourson, S. Briaudeau, S. G. R. Salim, K. Anhalt, M. Waehmer, D. R. Taubert, X. J. Feng, J. T. Zhang, X. F. Lu, H. Yoon
Summary: This paper discusses new developments in instrumentation and techniques for acoustic and radiometric primary thermometry methods. The work is ongoing, with the goal of ultimately providing consensus values of T-T-90 with associated estimated uncertainties.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Javier de Lucas
Summary: An experimental procedure for characterizing the size-of-source effect is proposed in this paper, which is an important factor causing uncertainty in the measurement of direct reading radiation thermometers. The procedure and uncertainty calculation described in the paper are aligned with the requirements of metrological traceability in industry and science. The results of applying and validating this procedure in the calibration laboratories of radiation thermometry in the industrial field are presented.
Article
Engineering, Multidisciplinary
Rui-Heng Sima, Xiao-Peng Hao, Jian Song, Hong Qi, Zun-Dong Yuan
Summary: With the proposed thermal resistance equivalent corrected method, an accurate numerical model was established to obtain the characteristic temperature of miniature fixed-point blackbodies, significantly reducing the error between calculated and experimental results.
Article
Instruments & Instrumentation
Javier de Lucas, Jose J. Segovia
Summary: Large-area blackbody cylinder conical cavities are widely used for calibrating and characterizing radiation thermometers and thermal imagers in the infrared. The radiated temperature depends on effective emissivity and contact temperature. The uniformity of the emitted radiation is influenced by the cone angle and temperature gradient along the cavity. The optimization of blackbody depends on geometric parameters and temperature.
INFRARED PHYSICS & TECHNOLOGY
(2023)
Article
Optics
Esteban D. Gadea, Carlos M. Bustamante, Tchavdar N. Todorov, Damian A. Scherlis
Summary: In this study, a recently introduced semiclassical model of light-matter interaction was explored, and it was found that it can reproduce the Boltzmann populations in two-level systems and predict black-body spectra in approximate agreement with Planck's distribution. In multilevel systems, small deviations from the expected occupations were observed, but these can be rationalized through a rate equation derived from the dissipative equation of motion.
Article
Instruments & Instrumentation
Ping Zhang, Jian Cao, Jin-bo Yuan, Dao-xin Liu, Yi Yuan, Yuan-fei Wei, Hua-lin Shu, Xue-ren Huang
Summary: The study presents an improved BBR temperature evaluation method by optimizing the ion trap structure and using a BBR shield to reduce uncertainty. By measuring the shield temperature with a platinum resistance temperature sensor outside the vacuum chamber, the BBR temperature uncertainty of the newly designed system was significantly reduced.
Review
Engineering, Chemical
Siyu Liu, Yu Huang, Yong He, Yanqun Zhu, Zhihua Wang
Summary: This paper summarizes and compares the main surface thermometry techniques used in combustion processes. It discusses both contact-based thermometry and non-intrusive thermometry methods. The advantages and disadvantages of these methods are analyzed, and special attention is given to radiation thermometry and laser-induced phosphorescence thermometry. The research progress and applications of these techniques are also discussed, highlighting the great development potential of laser-induced phosphorescence in surface thermometry.
Article
Instruments & Instrumentation
A. D. W. Todd, K. Anhalt, P. Bloembergen, B. B. Khlevnoy, D. H. Lowe, G. Machin, M. Sadli, N. Sasajima, P. Saunders
Summary: This study discussed two approaches to realizing temperature measurements using high temperature fixed-point blackbody cells, outlining the uncertainty components that need to be considered for each path and typical achievable values, focusing on Co-C, Pt-C, and Re-C.
Review
Engineering, Multidisciplinary
Botao Wang, Yanxiong Niu, Xudong Qin, Yiheng Yin, Ming Ding
Summary: This paper reviews high-temperature measurement technology based on sapphire optical fiber, focusing on sensing theory, sensor structures, and sensing performances of various sapphire fiber sensors.
Article
Thermodynamics
G. Failleau, N. Fleurence, O. Beaumont, R. Razouk, J. Hameury, B. Hay
Summary: The diffusivimeter of LNE has been modified to extend the operating temperature range up to 3000 degrees C, and a in-situ verification method based on miniature high temperature fixed-point cells has been proposed to ensure the accuracy of temperature measurements.
HIGH TEMPERATURES-HIGH PRESSURES
(2021)
Article
Optics
T. Zalialiutdinov, D. Glazov, D. Solovyev
Summary: This work examines the thermal correction to the hyperfine interaction in hydrogen, deuterium, and the 3He+ ion. The correction is described by one-loop Feynman graphs in the quantum electrodynamics theory at finite temperature. The obtained results are shown to be important for future measurements of hyperfine splitting and for testing the time variation of fundamental constants.
Article
Optics
Kaihua Zhang, Yanfen Xu, Weiling Gao, Kun Yu, Yufang Liu
Summary: This paper presents a systematic comparative analysis of the particle swarm optimization (PSO) algorithm and simulated annealing (SA) algorithm in the application of Multispectral radiation thermometry (MRT). The results indicate that the PSO algorithm outperforms the SA algorithm in accuracy, efficiency, and stability. The PSO algorithm is used to simulate the measured data of the surface temperature of a rocket motor nozzle, with a maximum absolute error of 16.27 K, a maximum relative error of 0.65%, and a calculation time of less than 0.3 s. The superior performance of the PSO algorithm suggests its potential for accurate temperature measurement in MRT and its applicability to various industrial processes under high temperature conditions.
Article
Optics
C. H. U. N. H. U. Yao, S. H. E. N. G. X. I. A. N. Shi, H. U. A. Fang, T. H. New
Summary: This paper presents a novel chameleon swarm algorithm approach for obtaining temperature information from light-field multi-wavelength data with higher accuracy without prior emissivity knowledge. Experimental tests show that the chameleon swarm algorithm outperforms traditional internal penalty function and generalized inverse matrix -exterior penalty function algorithms in terms of measurement accuracy and computational efficiency.
Article
Instruments & Instrumentation
T. Zhang, X. Lu, W. Dong
Summary: The study utilized the radiometry hybrid method, incorporating a lens to the irradiance method using a 900 nm filter radiometer, to measure the thermodynamic temperature of various fixed points at the National Institute of Metrology, China. Accurate estimation of effective diameters was achieved by scanning the uniformity of fixed-point blackbodies and considering the size of the source effect. The discrepancy between thermodynamic temperature and ITS-90 values for different fixed point blackbodies was concluded, with standard uncertainties estimated.
