Temperature measurements of high-temperature semi-transparent infrared material using multi-wavelength pyrometry

Fu, Tairan; Liu, Jiangfan; Tang, Jiahuan; Duan, Minghao; Zhao, Huan; Shi, Congling

doi:10.1016/j.infrared.2014.05.016

Cited by 25 publications

(12 citation statements)

References 44 publications

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“…For a smooth, flat, opaque surface, according to Kirchhoff's law, the Wien approximation formula, and the energy conservation law, the thermal emission spectral radiance, L, at wavelength λ, normal angle θ, polarization σ, and temperature T is given by: [14] Downloaded by [ [14,19] Actual measurements of the thermal emission and reflectance may only be achieved once light has been collected over a range of wavelengths, angles, and polarization states. The measured thermal radiation of a wafer is then expressed as:…”

Section: Measurement Methodsmentioning

confidence: 99%

Novel temperature calibration for epitaxial growth characterization

Yan

Lee

Wang

et al. 2015

Instrumentation Science & Technology

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A multi-probe in situ temperature monitoring system with a closed-loop process control has been developed using the technique of emissivity-compensated pyrometry for semiconductor epitaxial growth via metal-organic chemical vapor deposition. A standalone temperature calibration unit was designed to correct for reactor-to-reactor temperature variations. After calibration, a probe-to-probe temperature mismatch of less than ± 0.13 °C was obtained. Moreover, a temperature offset induced by the inevitable viewport deposition over time was demonstrated. A 4.28 °C temperature bias was successfully double-calibrated by introducing a compensation factor into the radiation equations, which was then validated during twelve processing runs of light emitting diode epitaxial growth.

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Section: Measurement Methodsmentioning

confidence: 99%

Novel temperature calibration for epitaxial growth characterization

Yan

Lee

Wang

et al. 2015

Instrumentation Science & Technology

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“…Multiwavelength pyrometer (MWP) temperature measurement technology is to obtain the real temperature of the object using the multiwavelength radiance information of the object 1 , 2 . The difficulty of MWP data processing method is that the data obtained through n spectral channels establish n radiation equations according to Planck formula, but there are n+1 unknowns (n unknown spectral emissivity and 1 unknown true temperature).…”

Section: Introductionmentioning

confidence: 99%

Generalized inverse matrix-recurrent neural network data processing algorithm for multiwavelength pyrometer

2022

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A generalized inverse matrix-recurrent neural network (GIM-RNN) data processing algorithm for unknown emissivity was proposed to measure high-temperature by multiwavelength pyrometer (MWP). First, emissivity classification was realized quickly according to a solution from generalized inverse algorithm to underdetermined multiwavelength equation group. According to the relationship between the emissivity of 2 adjacent channels of the 6 channel thermometer used in this paper, 243 emissivity models (1 Ã 3 Ã 3 Ã 3 Ã 3 Ã 3) were designed for classification. Twelve of them were shown on the schematic diagram in the text. To make the figure clear and easy to observe, the prediction results of six common emissivity models were listed as the experimental results. Then, it was input into the corresponding RNN subnetwork to inverse temperature precisely. Simulation results showed that in the range of 1500 to 3000 K temperature, the relative error of the test set was within 1.0% for the network trained after classification by GIM, whereas the relative error of the test set was within 1.2% for the network trained without GIM classification. After 5.0% random noise was added to the inputting data, the relative error still was controlled within 1.5%, which reflected the good antinoise performance of the algorithm. Multispectral measurement data of rocket engine plumes is processed by the proposed algorithm in this manuscript. The inversion results are consistent with the theoretical results. It is indicated that the proposed algorithm has good adaptability to different materials. It is expected to become a general data processing algorithm for MWP.

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“…Bichromatic thermography [19] assumes that the emissivity ratio at two wavelengths is known. Polychromatic thermography [6] is based on different emissivity modelling versus wavelength (polynomial, exponential, etc.). Active bichromatic thermography [2] adds equations to take into account strong parasite reflections on a specular metallic surface.…”

Section: Introductionmentioning

confidence: 99%

Effect and correction of the shift in spectral images for polychromatic thermography

Gilblas

Sentenac

2016

International Journal of Thermal Sciences

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This articles investigates the temperature errors due to chromatic aberration in multiwavelength thermography methods. The Chromatic aberration leads to a shift in the perspective projection of a point in the 3D space on the image formed at different wavelengths. This shift causes an error in the temperature field calculated by polychromatic methods, from the fusion for each pixel of radiance temperature images at different wavelengths. The temperature error can reach 40% on a sample with high spatial nonuniformities, due to wide variations of emissivity. This paper suggests an approach to correcting the chromatic aberration that is based not on equipment but on software, coupled with a calibration, using Digital Image Correlation (DIC). This experimental technique is a 2D optical method used in mechanical engineering, for inferring a deformation of a plane structure's surface from a displacement field calculated by correlation between pixels of two successive images. This paper applies the technique to achieve the field displacement induced between two images at two wavelengths by chromatic aberration. After applying this correcting displacement field, the temperature error decreases from 40% to 1% for the pixels located at the boundary of two areas with different emissivities.

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Temperature measurements of high-temperature semi-transparent infrared material using multi-wavelength pyrometry

Cited by 25 publications

References 44 publications

Novel temperature calibration for epitaxial growth characterization

Novel temperature calibration for epitaxial growth characterization

Generalized inverse matrix-recurrent neural network data processing algorithm for multiwavelength pyrometer

Effect and correction of the shift in spectral images for polychromatic thermography

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