Thermophysical Property Measurements on Niobium and Titanium by a Microsecond-Resolution Pulse-Heating Technique Using High-Speed Laser Polarimetry and Radiation Thermometry

A microsecond-resolution technique was used to measure the heat of fusion, specific heat capacity, and electrical resistivity of niobium and titanium in the temperature range of 1600 to 3200 and 1500 to 2200 K, respectively. The method is based on rapid resistive self-heating of a wire-shaped specimen by a current pulse from a capacitor–discharge system. Melting of the specimen occurs in approximately 50 s. Measured quantities are the current through the specimen, the voltage across the specimen, the radiance from the specimen, and its normal spectral emittance, as functions of time. The true temperature of the specimen is computed from the values of the normal spectral emittance and radiance temperature of the specimen at each instant. The latter quantities are measured by means of high-speed laser polarimetry and radiation thermometry, respectively.     

自校准地表/水表面红外辐射测温仪的研制

研制了一种具有自校准功能的测量地面或水表面辐射温度的仪器,阐述了该仪器的设计原理、具体结构、测试过程及最终的实验结果。为了验证仪器的性能,进行了定标黑体的发射率测量实验,控温稳定性试验,结果表明黑体发射率高于0.996,控温稳定性优于0.04 K;对各个温度传感器进行了标定校准;完成了控制与数据采集程序的编写;进行了样机的辐射测温实验。最后确定出自校准地水表面红外辐射测温仪的测温范围为223～333 K,测温不确定度为0.2 K。     

A Summary of Lightpipe Radiation Thermometry Research at NIST

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.     

红外辐射温度计专用数字表的研制及评价

日本CHINO公司生产的IR-RST系列标准辐射温度计由于没有设计温度显示装置,无法实时显示温度,针对此类型温度计设计了一款专用的电压测量和温度显示,同时可提供24V直流电压的电测显示仪表。利用高等级的电压源和数字电压表,修正了本专用数字表的误差系数,并考核了稳定性,得到其最大相对误差不超过0.03%。与一款名义波长为0.65 μm的IR-RST辐射温度计配合使用,通过TG HT-9500型高温炉对其组合进行内插分度,实验结果证实分度后校准准确度优于0.03%,1 300 ℃时系统测量结果的扩展不确定度为0.62 ℃。     

红外辐射温度计的辐射源尺寸效应修正

红外辐射温度计在低温测量的辐射源尺寸效应（SSE） 的规律不同于高温测量。基于以虚拟探测器温度消除背景辐射影响的SSE计算模型,推导了在不同源尺寸和不同背景条件下辐射温度计输出的SSE影响修正公式;得出不同源尺寸条件下辐射温度计温度示值的SSE影响修正的理论解析表达式。在源温度低于或接近背景温度时修正模型与高温测量SSE修正模型有显著差异。所得结果适用于任意温度下对单波段辐射温度计的SSE影响修正。     

环境温度对红外辐射式体温计读数的影响

本简要介绍了所研制的红外辐射式体温计的构成及标定实验方法；研究了环境温度对体温计的影响；并在实验基础上提出了采用分段标定及对环境温度补结果进行修正的方法，提出了测量精度。     

红外体温计示值修正值测得值的不确定度评定

本文选用二等标准铂电阻温度计作为标准器,恒温槽黑体作为黑体辐射源,对红外体温计进行了示值修正值的测量,分析了测量误差的来源和影响因素,并对测得值进行了不确定度评定。     

Thin-Film Thermophysical Property Characterization by Scanning Laser Thermoelectric Microscope

This work presents a scanning laser-based thermal diffusivity measurement technique for thin films as well as for bulk materials. In this technique, a modulated laser beam is focused through a transparent substrate onto the film–substrate interface. The generated thermal wave is detected using a fast-responding thermocouple formed between the sample surface and the tip of a sharp probe. By scanning the laser beam around the thermocouple, the amplitude and phase distributions of the thermal wave are obtained with micrometer resolution. The thermal diffusivity of the film is determined by fitting the obtained phase signal with a three-dimensional heat conduction model. Experimental results are presented for a 150-nm gold film evaporated on a glass substrate.     

坦克动力舱装甲板红外辐射温度计算分析

建立了坦克动力舱装甲板温度场数值计算模型,针对坦克动力舱装甲板的红外特性进行了理论计算.采用耦合计算方法计算了装甲板的温度场,通过装甲板和空气双向耦合换热计算,并考虑太阳辐射对装甲板温度场的影响,预测了装甲板温度场分布和辐射强度分布.动力舱装甲板温度场的计算结果与测试结果的相对误差小于9.034%,基本满足工程设计的需要.研究结果表明,动力舱顶装甲板是主要辐射源,排气百叶窗和排气管附近顶装甲板是坦克的红外辐射特征明显区域.     

A Universal Laser-Pulse Apparatus for Thermophysical Measurements in Refractory Materials at Very High Temperatures

This paper presents a new experimental technique enabling thermophysical measurements to be carried out at very high temperatures in a very simple and small pressurized vessel in which the sample is heated by a continuous wave laser, and subsequently subjected to a short temperature pulse. The adopted method is essentially an extension of the laser-flash technique, widely used for thermal diffusivity measurements, whereby, in addition, the heat capacity and, hence, the thermal conductivity, , are simultaneously evaluated from the pulse analysis. Results are presented for the thermal diffusivity and heat capacity of graphite, zirconia, and uranium dioxide up to temperatures above 3000 K.     

Middle Temperature Scale for Infrared Radiation Thermometer Calibrated Against Multiple Fixed Points

The NMIJ has established a temperature scale for infrared radiation thermometry from 100 to 420°C consisting of three fixed-point blackbodies at the In, Sn, and Zn points and an InSb detector thermometer at a wavelength of 4.7 μm. The blackbody cavities have large openings of 15 mm diameter. The expanded uncertainties (k = 2) of the In, Sn, and Zn fixed-point radiance temperatures are estimated to be 0.03, 0.03, and 0.05 K, respectively. The expanded uncertainties (k =  2) for the calibration of the infrared radiation thermometer are estimated to be 0.04 K at 157°C (In point), 0.04 K at 232°C (Sn point), and 0.07 K at 420°C (Zn point).     

Thermodynamic Radiation Thermometry for the Next SI

The construction, the calibration, and the use of the NIST Thermodynamic Radiation Thermometer (TRT) to measure the temperature of the gold freezing temperature blackbody and a variable-temperature blackbody from 800 to 2,700°C are described. These temperature determinations are detector-based and derived from the electrical substitution radiometer and length units. The TRT is constructed using a cooled, near-infrared enhanced silicon detector with a room-temperature-stabilized five-position filter wheel. The characteristics of the TRT, such as the size-of-source effect and preamplifier linearity, are determined. The measured temperatures are compared with those obtained using the NIST Absolute Pyrometer 1 (AP1) and the current NIST standard radiation thermometer, the Photoelectric Pyrometer (PEP). After the performance assessments, the TRT will become the standard radiation thermometer for disseminating radiance temperature scales in the United States.     

多彩氧化钨薄膜的红外电致变色性能研究

电致变色材料能够在可见-红外宽频谱范围内对吸收率、透过率、反射率和发射率进行动态调节,是人工调制材料光谱特征的有效手段。在实际应用场合,对于色彩(可见光)与热辐射(红外线)可控调节的需求往往并存,利用单一电致变色器件实现可见、红外双波段的光学调制性能具有重要意义。现阶段对于电致变色材料的设计主要集中于可见光谱的调节能力及颜色转变,忽略了对材料红外光谱的探究。本研究选取具有法布里–铂罗(F-P)空腔结构的多彩氧化钨薄膜进行可见–红外宽频谱电致变色探究,具有F-P空腔结构的氧化钨薄膜材料在可见光区呈现多样化、明亮的颜色,再对多彩薄膜进行图案化设计,即可得到具有各种图案的多彩薄膜,并且在外加偏压的作用下可以实现多样化的颜色转变。同时,多彩氧化钨薄膜的红外反射率也可获得明显的可控调制效果,在中波段(Medium Wave, MW)3.5μm左右处不同颜色薄膜均可获得高于25.00%的红外调制率。本研究表明,多彩氧化钨薄膜可以实现可见–红外宽频谱的分立、可控调节,在智能窗、热管理、辐射制冷等应用领域有巨大潜力,可达到光、热性能协同调制的效果。     

红外辐射温度计瞄准的平面辐射源模型

用典型红外辐射温度计的辐射源尺寸效应的实验数据说明不同测量条件下的检定/校准结果的差异可能为其最大允许误差绝对值的数倍。提出具有明确测量条件的平面辐射源瞄准模型和以辐射源前置光阑的方式对于不同空腔黑体辐射源实现相同的等效平面源直径的方法,提出了对光阑的技术特性和放置距离要求,分析表明低温辐射源对光阑的冷却作用可能引起不可忽略的示值降低。采用等效平面源模型的实验结果表明以不同几何条件的空腔黑体辐射源可得到一致的检定结果。讨论了应用平面辐射源模型可能遇到的实际技术问题和解决的对策。     

A Novel Method for Determination of the Thermal Diffusivity of Thin Films Using a Modulated CO<Subscript>2</Subscript> Laser

The thermal diffusivity of thin metal films has been measured by combining a fast infrared radiation thermometer with a mercury cadmium telluride (MCT) detector and a CO₂ laser modulated at a radio frequency up to 2 MHz. The laser output beam modulated by an acousto-optic modulator (AOM) is directed to the front surface of the blackened copper thin film (10m thick, 9.5 mm in diameter). The thermal radiation from the back surface of the sample is detected. From the observed phase delay in the detected signal of 0.68 radian to the input laser beam, the thermal diffusivity is determined to be 1.11 × 10^-4m²·s^-1, which agrees well with the value of 0.99 × 10^-4m²·s^-1 calculated from literature results. The method is generally applicable for measurements of thermal properties of nano/micro materials.Paper presented at the Fifteenth Symposium on Thermophysical Properties, June 22--27, 2003, Boulder, Colorado, U.S.A.     

基于OpenFlight模型的通用桥梁红外辐射特性模拟方法

对桥梁结构进行分析及简化,提出了基于OpenFlight模型的通用桥梁建模方法,将梁式桥、斜拉索桥、拱桥和悬索桥统一为一种通用的模型结构,并分别针对桥梁箱体结构、主缆、索塔、护栏等典型部件的热特性,综合考虑各种自然因素,建立桥梁红外辐射特性计算理论模型,并以图像的灰度信息模拟红外辐射特性,开发了通用的桥梁红外辐射特性计算及成像仿真软件系统,实现了任意时刻、任意地理位置、任意气象条件下不同类型桥梁的红外辐射特性模拟。实验结果表明提出方法与现有桥梁红外成像仿真结果具有一致性,符合典型桥梁的红外热辐射规律。     

红外微测辐射热计用纳米氧化钒薄膜的制备和性能研究

具有优异热敏性能的氧化钒薄膜材料是红外测辐射热计的首选热敏电阻材料，合适的薄膜电阻及高温度电阻系数的氧化钒薄膜的制备是实现高探测率红外测辐射热计的保证．利用新型对靶反应磁控溅射工艺制备了具有纳米颗粒的氧化钒薄膜材料，确定了最佳工艺参数．对其组成、结构和性能进行了分析，原子力显微镜AFM形貌分析表明薄膜具有均匀致密的表面，X射线光电子能谱分析XPS确定了其组成成分主要为V2O5,VO2和少量的V2O3.在常用作微测辐射热计结构层材料的氮化硅基底上，该薄膜材料在室温附近具有合适的薄膜电阻（大约为每方14kΩ）以及高的温度电阻系数（-3．17％／℃），有望适用于非致冷红外测辐射热计探测器．     

两类典型的低温应用红外探测材料研究

红外探测器件是现代军用武器装备目标识别的核心构件,而红外探测材料的性能将直接影响器件的性能水平。综述了两类典型的低温应用红外探测材料研究进展,以红外探测材料研究和应用的尺度为分类标准,分别对微米尺度的窄带隙直接半导体碲镉汞和基于量子效应的四种低维材料进行了介绍,并指出了当前红外探测材料研究存在的问题和发展的方向。     

红外光对魔芋葡甘聚糖的影响

以魔芋葡甘聚糖(KGM)为对象,红外辐照时间、辐照温度、KGM含水量及分子量为考察因子,单因素探讨了红外辐照对KGM品质的影响,同时运用静态激光光散射、扫描电镜、红外光谱及X射线衍射研究了红外辐照对KGM分子结构的影响。结果显示,KGM溶胶黏度下降率与分子量呈线性正相关,溶胶黏度随红外辐照温度升高和时间延长逐渐降低,辐照温度影响尤为显著;结构表征表明73℃的红外光照射能显著降低KGM分子量及结晶度,破坏其部分有序结构,主要为分子链氧化断链所致。