利用人工神经网络进行多光谱温度测量的研究

如何用辐射方法测物体的真实温度是长期存在的难题。本提出了一种测量目标真实温度的新方法,即基于神经网络模型的多光谱测温方法,并给出了仿真实验结果。     

多光谱测温技术研究

辐射温度是表征辐射热源的核心参数,要准确测试辐射温度首先须准确测试热辐射体的发射率。本文根据弹药爆炸时火焰辐射温度的特性和普朗克定律的适用性,采用多光谱的方法对火焰光谱发射率进行拟合运算和绝对辐射定标,研制了适合于弹药爆炸时火焰温度的多光谱测温设备,并进行了现场测试和分析,完成了火焰辐射温度的准确测试。     

辐射测温区域的界定分析

文章讨论了谱色测温系统研究中,基于测温坐标系的辐射测温区域的界定问题。以线性发射率模型以及改进的单调发射率模型为基础,通过测温坐标系标尺的考察,分析了不同光谱发射率模型下的辐射测温坐标系所限定的辐射测温有效区域的规律特征;以实际应用中特定的谱色测温仪器为例,给出该仪器适用的辐射测温的理论区域,并用黑体实验进行了验证。     

彩色测温方法中物体辐射色域的界定和划分

介绍了彩色测温方法的基本原理, 并基于可见光波段内光谱发射率的线性模型给出物体辐射颜色色品的表述; 明确了一个色品最多只能求解出两个温度; 解决了彩色测温方法中物体辐射色域的界定问题,并将辐射色域划分为温度单解域和双解域。     

神经多光谱辐射高温计的研制

研制成功一种新型的与发射率无关的多光谱辐射高温计。采用神经网络技术、棱镜分光技术，克服了以往需要假设发射率与波长函数关系以及光导纤维分光、干涉滤光片限定工作波长的缺点，可用于自动识别大多数工程材料的真温及光谱发射率。     

浅谈一种特定波长的辐射测温方法

本文提出了传统辐射测温的优点和缺点,并讨论了一种特定波长的辐射测温模型,通过对谱色测温法模型的数学分析得出了辐射测温的条件式,同时揭示了在一定波长下,这种测温方法理论上可以为辐射测温计量提供新的思路.     

一种新型红外多谱段高温计的研究

基于辐射学原理的辐射高温计是一种非常实用的非接触式表面温度测量仪器。但是,在许多的实际情况下,辐射测温的精度受到一定的影响,这主要是由于被测试件表面发射率的不解定性、较强的环境辐射等。本在研究了复杂环境中的辐射状况的基础上,提出了一种新的测温模型,并在此基础上建立了多谱段红外辐射高温计系统。实验证明,在环境辐射较强时,这种新型高温计系统达到了令人满意的结果。     

900 nm照度辐射温度计的研制

介绍了中国计量科学研究院基于黑体辐射原理研制的波长为900 nm、测温范围为600～1 500 ℃的照度辐射温度计。该辐射温度计测量探测器接收的光谱辐射照度,采用单点分度法,结合有效波长测量技术,直接依据普朗克辐射定律计算被测温度,具有结构简单、测温稳定性好的特点。单点分度法以Cu点为固定点在Al点测温偏差为-0.04 ℃,而在800 ℃和900 ℃两个点,与RT9032辐射温度计测量结果偏差分别为0.09 ℃和0.11 ℃。     

基于探测器的成象光谱仪绝对辐射定标方法

用一组窄带滤光片、简易辐亮度计和硅光二极管探测器设计了绝对型光谱辐亮度计。精确测量滤光片的光谱透过函数，计算辐亮度计的视场，标定探测器的绝对光谱响应度，成为绝对光谱辐亮度计，用来标定成象光谱和其它光学遥感器，并与基于光谱辐照度灯进行辐射定标的传统方法进行了比较。结果表明，基于探测器进行辐射定标的方法是一种提高光学遥感器定标精度的途径，而且是佐证其它定标方法可靠性的一种手段。     

辐射测温在钢铁工业中的应用及发射率对测量的影响

采用辅助吹气、侧面瞄准和底部瞄准3种辅助方法,并利用热电偶校正红外测温仪发射率的方法改进了测量钢板温度的辐射测温技术.研究结果表明:带氧化皮的钢板在1 μm附近的光谱发射率约为0.84,全波发射率约为0.85;若将工作波长为1 μm的红外测温仪的发射率设置在0.81～0.87之间,全辐射红外测温仪的发射率设置在0.83～0.87之间,则钢板在1 000 ℃时,单波长和全辐射红外测温仪因发射率波动而导致的测温偏差分别小于4 ℃和7.5 ℃.     

Radiation Thermometry Toward the Triple Point of Water?

The article describes and evaluates the possibility of using a high-temperature blackbody of accurately known thermodynamic temperature as a reference source for the determination of lower thermodynamic temperatures by spectral radiation thermometry. By applying various intermediate steps, this approach will allow spectral radiation thermometry to be used for the determination of the thermodynamic temperature of the triple point of water with a low uncertainty. The procedure for such an attempt is outlined, theoretical, and practical limits of the resulting uncertainty in thermodynamic temperature are given. The described experimental approach also provides a framework to calculate the uncertainties in determining the thermodynamic temperatures of the defining high-temperature fixed points of the International Temperature Scale of 1990 down to the triple point of water. The estimation of uncertainties is based on current and future values of the relevant contributing components. The uncertainty anticipated in determining the thermodynamic temperature of the triple point of water is 24 mK with current uncertainties and 1.9 mK in the future. Thus, the described approach yields uncertainties that are slightly higher, but comparable to, the tentative uncertainties of other methods—e.g., dielectric constant gas thermometry developed and applied within the framework of the new determination of the Boltzmann constant.     

Investigation and Elaboration of Methods of Multicolor Optical Thermometry

The various complex mathematical transformations previously proposed for eliminating methodological errors of multicolor radiation pyrometry are mainly reduced to the determination of such combinations of wavelengths or corrections of registered brightness for the spectral distribution of the radiating capacity of the object being thermometered at which its equivalent radiating capacity is equal to unity. Mathematical formulas of the determining parameters of multicolor pyrometry of radiation have been obtained. Engineering techniques for calculating the critical values of the determining and adjustable parameters at which the application of multicolor optical thermometry is excluded because of large errors have been developed. Algorithms of a priori and a posteriori calibration systems of multicolor pyrometry of radiation of objects with practically any spectral distribution of the radiating capacity are proposed.     

辐射发射与辐射法测温—如何接近表面真实温度

从辐射测法中辐射率变化对温度的影响，讨论了多色辐射测量法的发展与应用实践，比较了不同处理方法的优缺点。     

Thermodynamic Radiation Thermometry Using Radiometers Calibrated for Radiance Responsivity

Using radiometry, thermodynamic temperatures can be determined by a variety of experimental techniques. Radiometers without imaging optics can be calibrated for spectral power or spectral irradiance responsivity, and radiometers with imaging optics can be calibrated for radiance responsivity. These separate approaches can have different uncertainty components with different uncertainty values. At NIST, thermodynamic radiation thermometry is performed using radiation thermometers calibrated for radiance responsivity using laser-irradiated integrating sphere sources (ISS). The radiance of the ISS is determined using Si-trap detectors whose spectral power responsivity is traceable to the electrical substitution cryogenic radiometer. The radiometric basis of the NIST approach is discussed. The uncertainty budget for the measurements as well as the characterizations to determine the component uncertainty values is listed.     

Quantum Dot‐Based Thermal Spectroscopy and Imaging of Optically Trapped Microspheres and Single Cells

Laser‐induced thermal effects in optically trapped microspheres and single cells are investigated by quantum dot luminescence thermometry. Thermal spectroscopy has revealed a non‐localized temperature distribution around the trap that extends over tens of micrometers, in agreement with previous theoretical models besides identifying water absorption as the most important heating source. The experimental results of thermal loading at a variety of wavelengths reveal that an optimum trapping wavelength exists for biological applications close to 820 nm. This is corroborated by a simultaneous analysis of the spectral dependence of cellular heating and damage in human lymphocytes during optical trapping. This quantum dot luminescence thermometry demonstrates that optical trapping with 820 nm laser radiation produces minimum intracellular heating, well below the cytotoxic level (43 °C), thus, avoiding cell damage.     

辐射测温学研究进展

系统介绍了近年来辐射测淡不巫基础研究到应用研究的４个研究方向：热力学温度绝对测量，１ＴＳ－９０国际温标复现与比对，辐射法真温测量和应用技术研究，并针对辐射测温学的前沿课题提出了适宜于我国的研究方向。     

温度计量技术进展近况

近年来，在把ITS－90更方便地传递到工作用温度计，温度测量仪表采用信息技术和特殊工业场合测温应用方面均取得了一些进展。本文介绍了国内外温度技术在这些方面进展的状况。对温度定点，校验器，热电偶和热电阻测温，辐射测温，光纤测温和信息时代自动化系统中的温度检测仪表的重要进展分别作了介绍。     

Radiative Properties of Blackbody Calibration Sources:Recent Advances in Computer Modeling

The radiative characteristics (spectral effective emissivity, spectral radiance, and radiance temperature) of blackbody calibration sources widely used in radiation thermometry are an important subject for advanced computer modeling by the Monte Carlo method. An algorithm and code for stochastic modeling of the radiant heat transfer inside cavities has been developed on the basis of the reciprocity principle and backward ray tracing. The importance sampling technique has been applied to generate the reflected rays according to the surface reflection model that can be a linear combination of the following primary models: Lambertian, Specular, and TETRA (a microfacet model of random tetrahedral pits that mimics reflections from a rough surface). A wide range of axisymmetrical cavities, cylindrical cavities with an inclined flat bottom, and a rectilinear grooved radiator of polygonal profile have been implemented. Various conditions of observation can be modeled to compute appropriate radiation characteristics. A number of different temperature distributions can be assigned to the same node set on the cavity surface, so several related tasks can be modeled in a single run. The results obtained for the radiative properties of isothermal and non-isothermal non-diffuse blackbodies used for the calibration of infrared radiation thermometers are presented and discussed.     

Emissivity modeling of metals during the growth of oxide film and comparison of the model with experimental results

Emissivity modeling of metals has been developed to elucidate behavior during the growth of oxide film, and the modeling results have been compared with experimental results. To express emissivities, pseudo-optical constants of a bare metal and of an oxide film obtained by an elipsometer are substituted into the model equations. Emissivity behavior during the growth of an oxide film upon the surface of a specimen is shown in terms of spectral, directional, and polarized characteristics, and it coincides with the experimental results, both quantitatively and qualitatively. The modeling is simple and provides useful guidance for the development of emissivity-compensated radiation thermometry.