Measurements of Temperature and Emissivity Distributions on a High-Temperature Surface Using an Auxiliary Light Source Method

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Tairan Fu ◽  
Yehan Xiong ◽  
Jiangfan Liu ◽  
Congling Shi
Keyword(s):  
High Temperature ◽  
Light Source ◽  
Measurement Method ◽  
Sample Surface ◽  
Optical Pyrometer ◽  
Alloy Sample ◽  
Thermocouple Method ◽  
Uncertainty Models ◽  
Effective Radiation ◽  
Color Channels

A method to simultaneously measure two-dimensional temperature and emissivity distributions on high-temperature diffuse surfaces is developed using an auxiliary light source. The high-temperature diffuse surface is irradiated from the hemispherical space with the auxiliary light source switched “on” or “off.” Two images of the effective radiation intensity are obtained in quick succession for the two states to determine the temperature and emissivity distributions. The measurement method and uncertainty models show that the effect of the unknown emissivity on the accuracy of the temperature field measurement can be eliminated. The optical pyrometer is a color charge coupled device (CCD) sensor with a quartz lamp array used as the auxiliary light source to illustrate the measurement method. An oxidized W–Ni–Fe alloy sample is heated at high temperatures of 600–1000 °C by a 700 W induction-heating device. The distributions of the effective radiation intensities from the sample surface during the “on” and “off” states of the lamp array are measured in the three color channels (R, G, and B channels) to calculate the temperature and emissivity distributions. The temperature measurement uncertainties are less than 4 °C for a temperature range of 600–900 °C. The temperature measurements are experimentally validated by the thermocouple method only with a small temperature difference. The emissivities calculated from the three color channels are very close with a range of 0.855–0.957. The relative uncertainties in the emissivities for channels R and G are less than 2.0%, while the relative uncertainty for channel B data was higher at 2.8% and 7.5% due to lower measurement signals in channel B. This analysis may provide a useful method for measuring the temperatures of high-temperature diffuse surfaces by successfully compensating for the effects of unknown or changing emissivities.

scholarly journals High-Temperature Elastic Properties of Yttrium-Doped Barium Zirconate

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata
Keyword(s):  
High Temperature ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Measurement Method ◽  
Young's Modulus ◽  
Barium Zirconate ◽  
Shear Moduli ◽  
Ceramic Fuel ◽  
Yttrium Concentration ◽  
Ceramic Fuel Cells

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.

Light Source, Excitation, and High Temperature Cell Assembly for Raman Spectroscopy

1961 ◽  
Vol 15 (2) ◽  
pp. 47-52 ◽  
Author(s):  
George J. Janz ◽  
Yukio Mikawa ◽  
David W. James
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Light Source ◽  
Cell Assembly ◽  
Source Excitation

The measuring system for monitoring the microarc heating process during surface hardening of steel products

2021 ◽  
pp. 33-39
Author(s):  
Makar S. Stepanov ◽  
rina G. Koshlyakova
Keyword(s):  
Heat Treatment ◽  
Mathematical Model ◽  
Electric Current ◽  
Measurement Method ◽  
Sample Surface ◽  
Steel Sample ◽  
Measuring System ◽  
Heating Process ◽  
Carbon Powder ◽  
Measured Temperature

The accelerated heat treatment during steel products hardening technology has been investigated. The possibility of measuring the temperature of steel products by thermoelectric platinum-platinum-rhodium thermocouple under microarc heating conditions is analyzed. During the experiments, working junctions of two S-type thermocouples: working and standard, were coined into the sample surface at the same level. The free thermocouples ends were connected to a digital multimeter and a personal computer. It was determined that 5 factors affect the measurement results: the electric current strength in the circuit, carbon powder, calibration, number of repeated measurement cycles, and a thermocouple copy. When planning the experiment, the concept of conducting a step-by-step nested experiment was used. Variance analysis method was used to process the experimental results. The measurement method precision parameters were calculated: repeatability and reproducibility. A linear mathematical model linking the measurement method reproducibility index with the measured temperature value has been obtained. A linear mathematical model is obtained that relates the reproducibility index of the measurement method to the measured temperature value. A measuring system for the experimental determination of the temperature of a steel sample is proposed and its application is justified for different electric current densities on the sample surface and varying duration of microarc heating. The possibilities of selecting and controlling the microarc heating modes depending on the required temperature of the heat treatment of the steel product are determined.

scholarly journals Carbonization and Treatment the High Temperature Distortion of Thoriated Tungsten Cathode for High Power Electronic Tubes

2009 ◽  
Vol 6 (4) ◽  
pp. 763-769
Author(s):  
Baghdad Science Journal
Keyword(s):  
High Temperature ◽  
High Power ◽  
Vacuum Chamber ◽  
Optical Pyrometer ◽  
Power Electronic ◽  
Heat Treated ◽  
Pressure Time ◽  
Thoriated Tungsten ◽  
Distortion Effect ◽  
Different Diameters

A metal mandrel was designed for manufacturing the cathodes of high power electron tube ( Tetrode ) used in broadcasting transmitting tubes type TH558 and CQS200.The cathodes were manufactured in the present work from thoriated tungsten wires ( 2? ThO2- W) with different diameters .These cathodes were carbonized in sequences of processes to determine the carbonization parameters (temperature, pressure, time, current and voltage).Then the carbonized cathodes dimension were accurately measured to determine the deviation due to the high temperature distortion effect at about 1800°C .the distorted cathodes due to the carbonization process was treated when it was subjected inside the vacuum chamber and heat treated again .The carbonized cathode distortions as a function of temperature were measured in the range of (1500°C-1800°C).The temperature was determined using an optical pyrometer and also calculated using Stephan's-Boltzmann relation.

Measurement Method of Infrared Radiometric Characteristics for High-Temperature Small Targets

2017 ◽  
Vol 37 (10) ◽  
pp. 1012004 ◽  
Author(s):  
田棋杰 Tian Qijie ◽  
李 周 Li Zhou ◽  
常松涛 Chang Songtao ◽  
何锋赟 He Fengyun ◽  
乔彦峰 Qiao Yanfeng
Keyword(s):  
High Temperature ◽  
Measurement Method ◽  
Small Targets ◽  
Radiometric Characteristics

scholarly journals Impact of different standard lighting sources on red jadeite and color quality grading

2019 ◽  
Vol 23 (4) ◽  
pp. 371-378
Author(s):  
Xin Pan ◽  
Ying Guo ◽  
Ziyuan Liu ◽  
Zikai Zhang ◽  
Yuxiang Shi
Keyword(s):  
Light Source ◽  
Color Space ◽  
Sample Surface ◽  
Color Temperature ◽  
Integrating Sphere ◽  
Light Sources ◽  
Light Spectrum ◽  
Fisher Discriminant Analysis ◽  
Fisher Discriminant ◽  
Quality Grading

The purpose of this paper is to investigate the standard light source for grading and displaying the color of red jadeite and to classify the color. With Raman spectrometer, ultraviolet-visible spectrophotometer and X-ray fluorescence spectrometer, the results show that, the Fe 3+ is the main chromogenic mineral of red jadeite, which negatively correlates with the tonal angle, while the color of red jadeite has a positive correlation with the hematite content. The color of 120 red jadeite samples was examined by collecting the reflective signaled from the sample surface using an integrating sphere with the portable X-Rite SP62 spectrophotometer based on CIE 1976 L*a*b* uniform color space. The color parameters of jadeite samples under D65, A and CWF standard light sources were analyzed. The light spectrum of D65 light source is continuous, relatively smoothed with high color temperature, which makes the sample color close to that under the natural light and can be used as the best evaluation light source. A light source contributes to improve the red tone of jadeite, which is the best light source for commercial display of red jadeite. CWF light source can be used as the auxiliary lighting for color evaluation. The color of red jadeite is divided into five levels from best to worst using K-Means cluster analysis and Fisher discriminant analysis under D65 light source: Fancy Vivid, Fancy Deep, Fancy Intense, Fancy dark and Fancy.

Valence Band Spectroscopy in the Ultrasoft X-Ray Region (50 to 100 A)

1975 ◽  
Vol 19 ◽  
pp. 627-641 ◽  
Author(s):  
Burton L. Henke ◽  
Kazuo Taniguchi
Keyword(s):  
Measurement Method ◽  
Emission Spectra ◽  
Sample Surface ◽  
Electron Excitation ◽  
Low Energy ◽  
High Dispersion ◽  
Simple Method ◽  
X Ray ◽  
Molecular Layers ◽  
Illustrative Application

Transitions from the valence electron levels into the first relatively sharp inner sub-shell levels result in characteristic x-ray emissions in the 100-200 eV region. These spectra sensitively reflect the chemical state of the atoms which are representative of the submicron thickness of the sample surface under low energy x-ray excitation and of the first few molecular layers of the sample under electron excitation.An optimized measurement method for this 50-100 A spectral region is “based upon single crystal spectrometry using a lead stearate analyzer which has high dispersion and efficiency and an energy width of about one eV in this wavelength range. Spectra are recorded using “tuned” proportional counter detection. In the work reported here, low energy x-ray excitation is used in order to minimize the possibility of radiation damage of the sample.Each spectrum is calibrated for both energy and instrument transmission using known, sharp M lines of elements such as molybdenum, zirconium and yttrium which will bracket the spectraj. range under measurement. A simple method has been developed for "stripping" from the measured spectra the Lorentzian crystal width and the Gaussian collimation width in order to allow an estimation to be made of the actual emission line widths as well as the relative intensities.In this report, as an illustrative application example, S-LII, III spectra are presented for a series of sulfur compounds in "both solid, and gas states. Manne's approximate molecular orbital interpretation of the x-ray emission spectra has been adopted and extended to apply to the LII, III spectra for second row elements.

scholarly journals High Temperature Texture Goniometer for in Situ Measurements of Transformation Textures

1998 ◽  
Vol 30 (3-4) ◽  
pp. 125-132
Author(s):  
G. Brückner ◽  
F. R. Reher ◽  
G. Gottstein
Keyword(s):  
High Temperature ◽  
Texture Evolution ◽  
Sample Surface ◽  
Texture Measurement ◽  
X Ray ◽  
Reducing Gas ◽  
Gas Atmosphere ◽  
Computer Controlled

A high temperature stage was designed for mounting onto a computer controlled four circle X-ray texture goniometer. This technique allowed to conduct in situ texture measurement, i.e. the determination of the texture evolution during rather than subsequent to annealing. The device was employed for temperatures up to 1000°C.The furnace consisted of a resistance wire of Pt30Rh, which was isolated against the specimen with Al2O3 glue. The furnace with the specimen was covered by a hemispherical KaptonTM foil. Inside the hemisphere a reducing gas atmosphere was used to avoid oxidation of the sample surface.

scholarly journals Use of double Göbel mirrors with high-temperature stages for powder diffraction – a strategy to avoid severe intensity fade

2003 ◽  
Vol 36 (3) ◽  
pp. 926-930 ◽  
Author(s):  
Pamela S. Whitfield
Keyword(s):  
High Temperature ◽  
Sample Surface ◽  
Parallel Beam ◽  
Sample Height ◽  
Severe Intensity ◽  
Computer Controlled ◽  
High Temperature Stage ◽  
Full Temperature ◽  
Intensity Loss ◽  
Mirror Configuration

This paper describes an approach for countering an issue that can occur when using a high-temperature stage with a diffractometer equipped with double Göbel mirrors. The optical characteristics of the dual-mirror configuration make it more susceptible to intensity loss with sample displacement than conventional parallel-beam secondary optics. This issue has been apparent in the use of a high-temperature stage on a diffractometer equipped with dual mirrors, where data could not be obtained from the full room temperature to 1273 K range without resetting the sample height manually part way through the experiment. A simple technique involving controlled contouring of the sample surface has been demonstrated to allow data to be collected uninterrupted over the full temperature range, while retaining satisfactory intensities. The extent to which this technique extends the tolerable sample displacement range has been quantified using a computer-controlledXYZstage.

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