共查询到19条相似文献,搜索用时 280 毫秒
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经典的短波高温修正模型不适用于中长波红外温度计的发射率修正和不确定度评定。采用有效亮度温度概念,得到了对于温度范围和测温波长具有广泛适用性的发射率影响模型以及具有简明物理含义的微差近似形式,包含了经典亮度温度理论中的发射率影响修正和环境辐射误差修正。定量分析了经典的短波高温修正模型的误差。针对黑体辐射源的不同溯源方法,讨论了辐射温度计校准中的发射率影响修正方法,并给出修正实例。所用方法可用于辐射测温应用、辐射温度计校准和黑体辐射源校准中的发射率和环境影响修正以及辐射源发射率不确定度对校准结果不确定度贡献的计算。 相似文献
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黑体辐射源的有效发射率影响是辐射测温计量标准中的重要影响因素.本文利用有效亮度温度概念,对辐射温度计或黑体辐射源检定校准中的发射率影响修正模型的多种简化形式进行了分析比较.定量分析了Wien近似、忽略环境辐射近似和微差近似等几种近似模型的温度与波长适用性.其中微差模型具有简明的物理含义,经典的短波高温修正模型不宜用于常见的8~14μm辐射温度计的测量结果修正.在有效亮度温度测量与校准的发射率修正和不确定度传播计算中,本文分析结果为在不同波长和温度范围合理选择简化公式提供了参考依据. 相似文献
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黑体辐射源发射率对辐射测温准确度的影响及修正方法 总被引:5,自引:0,他引:5
随着辐射温度计的广泛应用,对准确测量、校准或检定的要求越来越高.尽管黑体辐射源的性能不断提高,但黑体辐射源发射率偏离1仍然是影响辐射温度计校准/检定或相关应用准确度的关键问题.可是目前对辐射温度计的校准常常忽略黑体辐射源发射率偏离1的影响或在分析中采用不适当的计算.针对常见的辐射温度计,阐述了对黑体辐射源发射率的影响进行修正与不确定度评定的一般方法,对复杂的宽带辐射温度计提出可行的近似计算方法,并对最常见的8~14μm宽带辐射温度计给出了计算结果.分析结果表明,对于较长波长的辐射温度计,在中高温区的校准或检定中所经常使用黑体辐射源发射率值所引起的亮度温度误差是显著的,应予以修正. 相似文献
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介绍了中国计量科学研究院研制的100~400K真空红外亮温标准黑体辐射源的工作原理、结构、性能测试方法及测试结果。黑体辐射源通过液氮制冷与3温区控制实现了100~400K范围内的温度控制。在真空环境下,测试了其在温度范围100~400K轴向温度均匀性、底部温度稳定性等技术指标,结果表明均匀性优于0.120K,控温稳定性优于0.020K/20min;在室温大气环境下,利用基于控制环境辐射的发射率测量方法测量了黑体空腔发射率,空腔法向发射率为0.9998。采用基于蒙特卡罗黑体发射率仿真计算方法分析轴向温度均匀性对空腔发射率的影响,分析了标准黑体辐射源的不确定度来源,在8~16 μm波长亮度温度的合成标准不确定度优于0.030K。 相似文献
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介绍了中国计量科学研究院为风云三号05星红外高光谱大气探测仪研制的微型镓固定点星载黑体辐射源。设计了黑体辐射源空腔,其有效发射率优于0.997。针对星载固定点黑体辐射源的结构设计和性能测试展开了研究:星载固定点黑体辐射源17 ℃的温度均匀性仿真结果优于0.01℃;黑体辐射源在真空下均匀性优于0.02 ℃,稳定性优于0.002 ℃(90 min内);在通过满足航天应用的力学冲击等实验后,镓固定点的复现性优于0.03 ℃;微型固定点相变温坪复现实验加热功率与拐点值之间存在较好的线性关系。 相似文献
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Benjamin K. Tsai 《Journal of research of the National Institute of Standards and Technology》2006,111(1):9-30
During the last 10 years, research in light-pipe radiation thermometry has significantly reduced the uncertainties for temperature measurements in semiconductor processing. The National Institute of Standards and Technology (NIST) has improved the calibration of lightpipe radiation thermometers (LPRTs), the characterization procedures for LPRTs, the in situ calibration of LPRTs using thin-film thermocouple (TFTC) test wafers, and the application of model-based corrections to improve LPRT spectral radiance temperatures. Collaboration with industry on implementing techniques and ideas established at NIST has led to improvements in temperature measurements in semiconductor processing. LPRTs have been successfully calibrated at NIST for rapid thermal processing (RTP) applications using a sodium heat-pipe blackbody between 700 °C and 900 °C with an uncertainty of about 0.3 °C (k = 1) traceable to the International Temperature Scale of 1990. Employing appropriate effective emissivity models, LPRTs have been used to determine the wafer temperature in the NIST RTP Test Bed with an uncertainty of 3.5 °C. Using a TFTC wafer for calibration, the LPRT can measure the wafer temperature in the NIST RTP Test Bed with an uncertainty of 2.3 °C. Collaborations with industry in characterizing and calibrating LPRTs will be summarized, and future directions for LPRT research will be discussed. 相似文献
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大口径高发射率面型黑体辐射源的研制 总被引:1,自引:0,他引:1
黑体辐射源作为定标标准器,在红外测量设备的辐射定标中具有重要作用。为应对大口径红外测量设备的辐射定标工作需求,设计了1台辐射面积为400mm×400mm的面型黑体辐射源。采用多路控温和连接固定冷源的方式对黑体进行温度控制;通过热仿真确定合适的传热模型,同时结合高发射率涂层工艺与辐射面的结构设计使黑体具备高发射率,辐射面有效发射率可达到0.992;在真空环境下,利用标准铂电阻温度计测量得到黑体辐射面源的温度均匀性偏差最大为0.101K,稳定性平均值为0.018K/10min,该黑体辐射光源能够满足现阶段大口径红外测量设备的使用需求。 相似文献
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S. N. Mekhontsev V. B. Khromchenko L. M. Hanssen 《International Journal of Thermophysics》2008,29(3):1026-1040
The realization and the dissemination of spectral radiance and radiance temperature scales in the temperature range of −50
to 250°C and spectral range of 3–13 μm at the National Institute of Standards and Technology are described. The scale is source-based
and is established using a suite of blackbody radiation sources, the emissivity and temperature of which have been thoroughly
investigated. The blackbody emissivity was measured using the complementary approaches of modeling, reflectometry, and the
intercomparison of the spectral radiance of sources with different cavity geometries and coatings. Temperature measurements
are based on platinum resistance thermometers and on the direct use of the phase transitions of pure metals. Secondary sources
are calibrated using reference blackbody sources, a spectral comparator, a controlled-background plate, and a motion control
system. Included experimental data on the performance of transfer standard blackbodies indicate the need for development of
a recommended practice for their specification and evaluation. Introduced services help to establish a nationwide uniformity
in metrology of near-ambient thermal emission sources, providing traceability in spatially and spectrally resolved radiance
temperature, spectral radiance, and background-corrected effective emissivity. 相似文献
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A new technique has been developed for the direct measurement of the normal spectral emissivity at several wavelengths in pulse-heating conditions, adding some novel features to previous versions of this type of apparatus. Pulse-heating experiments were performed on niobium strip specimens, taking the specimen from room temperature to the melting point using rapid resistive self-heating. The normal spectral emissivity was measured at three wavelengths by a multi-wavelength reflectometric technique. At the same time, the radiance temperature was measured at the same wavelengths by a high-speed pyrometer from approximately 1100 K to the melting point. Details of the method, the measurement apparatus, and the calibration technique are described. Preliminary results for the normal spectral emissivity of niobium at 633, 750, and 900 nm over a wide temperature range are presented. 相似文献
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在辐射温度计检定中,根据规程要求,需要将辐射温度计的发射率设置为1,而在实际校准辐射温度计的过程中发现大量发射率固定且不为1的情况,同样有用户要求校准后给出不同发射率下的辐射温度计修正值,为实现宽波段任意固定发射率辐射温度计在校准过程中的修正值计算,文章使用LabVIEW的两分法迭代实现Plank公式的积分算法,有效提高校准过程的自动化程度,文章用实例说明了两分法与普通步进算法的效率区别,从而高效的实现了任意波段、任意发射率、任意温度点的温度修正值计算。 相似文献
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Joel B. Fowler 《Journal of research of the National Institute of Standards and Technology》1996,101(5):629-637
A high temperature oil-bath-based-black-body source has been designed and constructed in the Radiometric Physics Division at the National Institute of Standards and Technology, Gaithersburg, MD. The goal of this work was to design a large aperture blackbody source with highly uniform radiance across the aperture, good temporal stability, and good reproducibility. This blackbody source operates in the 293 K to 473 K range with blackbody temperature combined standard uncertainties of 7.2 mK to 30.9 mK. The calculated emissivity of this source is 0.9997 with a standard uncertainty of 0.0003. With a 50 mm limiting aperture at the cavity entrance, the emissivity increases to 0.99996. 相似文献
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S. G. R. Salim E. R. Woolliams N. P. Fox 《International Journal of Thermophysics》2014,35(3-4):504-515
This paper describes a method to calibrate photodiode array spectrometers in the spectral radiance mode using a fixed-point blackbody as a reference source. Fixed-point blackbodies are characterized by their excellent emissivity, uniformity, and stability, which make them superior to both conventional standard lamps and variable temperature blackbodies. The temperature of these fixed points is accurately determined being traceable to either the International Temperature Scale (ITS-90) or thermodynamically through radiometric standards. The potential advantage of the fixed-point traceability chain is that it can be universally reproduced without recourse to any hierarchical calibrations or standards. The paper presents the calibration system and discusses the limitations of such an approach. The method used obtained an uncertainty of around 1.4 % ( \(k = 2\) ) associated with radiance responsivity across the spectral region from 550 nm to 1050 nm, which is comparable to what is readily achieved with a lamp-tile or lamp-illuminated spherical source. 相似文献
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简要地介绍了国内外在黑体辐射源建立与评价上的发展现状;多种黑体辐射源;多种空腔有效发射率计算方法和模型。通过积分法推导出温度均匀空腔有效发射率计算公式,进一步推导的近似计算公式可以作为对黑体空腔有效发射率估算的依据。 相似文献