有效亮度温度测量中发射率影响的修正

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。     

一种可同时测量发射率及温度的被动式测温系统

介绍了一种实用化实时测温系统.该系统采用了PIN硅光电二极管作光接收器件,由光学接收系统、信号放大与处理系统及显示系统三部分组成.从系统的相对测温灵敏度及探测器的温度分辨率与波长间的关系出发,结合大气对红外辐射的透射特性,确定了系统的工作波长;从系统的抗反射辐射能力出发,并结合探测器的最小可探测光功率要求,确定了系统的波长带宽.从辐射能P1、P2的测量不确定度出发,讨论了待测目标的发射率及温度的测量精度.结果表明,当λ=0.80 μm、△λ=20 nm时,在测温范围600～2 500℃内,系统的测温不确定度优于0.3%,满足设计要求.     

有效亮度温度理论

经典亮度温度和有效波长理论忽略了环境辐射的影响,且实际测温理论偏离了亮度温度的定义.考虑了环境辐射影响,提出新的有效亮度温度概念,使有效亮度温度适用于存在环境辐射的任意温度测量;进一步提出了基于带通辐射温度计测量的积分有效亮度温度和等效波长理论,使辐射温度计的主观测量结果与物体的客观辐射特性相联系,避免了实际测量理论偏离被测量定义.     

Uncertainties in the Realization of Thermodynamic Temperature Above the Silver Point

Recent advances in high-temperature thermometry have opened up the possibility of realizing and disseminating thermodynamic temperatures above the silver point by means of both primary radiometry and radiation thermometry with the aid of high-temperature fixed points with known thermodynamic temperatures. A variety of realization schemes, denoted n = 0, 1, 2, 3, 3+, where n refers to the number of fixed points used in the realization, are described in new sections of the ??Mise en pratique for the definition of the kelvin.?? A major advantage of this approach is flexibility, accommodating the varying resources and needs of a wide range of laboratories and/or users. This article outlines the uncertainty analysis for each of the n ?? 0 schemes, which provides a means for assessing the suitability of any particular scheme and for selection of the appropriate fixed points. In all cases, the analysis is based on a modified Sakuma?CHattori model of the radiometer response. This model allows simple analytical expressions to be derived for all sensitivity coefficients, identification of the dominant uncertainty components, and each scheme to be easily compared. Current best estimates for each uncertainty component are given, and these are propagated to give a total uncertainty for each scheme.     

Adiabatic Calorimetry Approach to Assess Thermal Influences on the Indium Melting Point

Within the framework of the Euramet project 732, LCM/LNE-CNAM has recently proposed a new device to investigate the melting point of indium (156.5985 °C) by the way of an adiabatic calorimetry approach. An apparatus based on a cell-within-cell configuration was developed and experimentally tested. First results highlighted parasitic heat flows due to the geometrical characteristics of the cell, disturbing significantly the isothermal condition within the calorimeter. Such thermal effects were also clearly identified with a specific numerical model developed for this purpose. Considering the remarkable agreement between the model and relevant experiments, an optimization step has been carried out to design a suitable cell geometry. A new enhanced cell was subsequently fabricated and arranged within the calorimeter (indium load of 122.32 g). The purpose of this article is to introduce the thermal behavior of such a highly effective apparatus, while presenting some series of measurements; on the one hand, the melting point of indium under adiabatic conditions is studied, and on the other hand, the so-called continuous heat flow method under isothermal conditions is worked out. The obtained results are discussed and analyzed according to the impurity concentrations into the ingot (sum of individual estimate method).     

Measurement of Melting Point and Radiance Temperature (at Melting Point and at 653 nm) of Hafnium-3 (wt. %) Zirconium by a Pulse Heating Method

A subsecond duration pulse heating method is used to measure the melting point and radiance temperature (at 653 nm) at the melting point of hafnium containing 3.12 weight percent zirconium. The results yield a value of 2471 K for the melting point on the International Practical Temperature Scale of 1968. The radiance temperature (at 653 nm) of this material at its melting point is 2236 K, and the corresponding normal spectral emittance is 0.39. Estimated inaccuracies are: 10 K in the melting point and in the radiance temperature, and 5 percent in the normal spectral emittance.     

基于仿人智能的煤的燃点测定

提出基于仿人智能技术的煤的燃点测定新方法。为克服电炉数学模型大范围变化的问题,采用仿人智能控制算法设计了炉温控制器。运用仿人智能技术识别煤的燃点,这种方法吸收了人工识别时逻辑推理的长处,克服了人工识别的主观随意性。实验结果表明,其测量平行误差小于1℃,适合于用氧气作氧化剂时煤的燃点测定。     

Thermodynamic Temperature Measurements Traceable to Photometric Standards

The replacement of ITS-90 temperature measurements by direct thermodynamic temperature measurements based on radiometric techniques in the temperature range above 1000 °C has been proposed by many national measurement laboratories. This article reports on work at NMIA to develop a simple and robust traceability scheme for thermodynamic temperature, based on the use of photometers and a Thermogage furnace with a graphite tube element modified to improve its temperature uniformity and emissivity. A simple luminance meter was constructed using a commercial photometer and pairs of precision apertures to view the rear of the blackbody cavity. This photometer was calibrated against NMIA reference illuminance lamps, and relative spectral responsivity measurements were used to determine the color-temperature correction between the lamps and the Thermogage blackbody. Thermodynamic temperature determinations made using various combinations of apertures and photometers showed a range of less than 0.2 °C at 1700 °C, consistent with the calculated uncertainty of 0.29 °C (k = 2). ITS-90 measurements made by NMIA??s LP5 and HTSP primary radiation thermometers with an uncertainty of 0.16 °C (k = 2), are consistent with the thermodynamic measurements. It is suggested that routine thermodynamic temperature determinations can now be made with an effort comparable to that required to realize the ITS-90 above 1000 °C.     

NMIJ Constant-Volume Gas Thermometer for Realization of the ITS-90 and Thermodynamic Temperature Measurement

The constant-volume gas thermometer (CVGT) of the National Metrology Institute of Japan (NMIJ), AIST with ³He as the working gas is used as an interpolating gas thermometer to realize the International Temperature Scale of 1990 (ITS-90) from 3 K to 24.5561 K and as a relative gas thermometer for thermodynamic temperature measurement calibrated at the triple point (TP) of Ne. The standard uncertainties of the realization and measurement are estimated to be 0.58 mK and 0.86 mK at a maximum in the mentioned temperature range, respectively. The maximum difference between both temperatures is about 1 mK. In the calibration of the CVGT, the TP of equilibrium hydrogen (e-H₂) is corrected for isotopic composition as specified in the Technical Annex for the ITS-90. The ambiguity of the TP of Ne due to the variability in isotopic composition is included in the uncertainty. Although the CVGT was also used in 2004 to realize the ITS-90, it was modified for the present experiment to reduce some measurement uncertainty components and the working gas was replaced with a higher-isotopic-purity gas. The results from 2004 were recalculated by correcting for the isotopic composition of e-H₂ and differ insignificantly from the present results, except for a wider scatter.     

Realization of the Indium Fixed Point by an Adiabatic Technique

This work investigates the effect of heating techniques on the realization of the ITS-90 fixed points above room temperature. For that purpose, LNE has constructed a new apparatus to realize the indium fixed point under adiabatic conditions using the “calorimetric” method. The adiabatic condition, in general, is established by maintaining a temperature difference between the fixed-point cell and its surroundings that is as small as possible. In this work, the indium fixed-point cell is located within thermally controlled heat shields whose walls also contain indium. Thus, the shields themselves are also indium cells. The experiments realizing the melting and freezing temperatures of indium using the calorimetric method are described. The results revealed the existence of thermal effects in the realization of the indium fixed-point cell by the conventional “continuous heat flux” method. The advantages of the “cell-within-cell” technique are presented.     

多种体温测量方法的比较

本文采用三种不同的体温测量方法,收集89例患者的体温,每种方法各收集到有效数据845个.通过对体温数据的处理分析,探索耳温、额温、肛温三者的关系.额温均数标准差:(37.12±0.32)℃;耳温的均数标准差:(37.37±0.47)℃;肛温的均数标准差(37.53±0.31)℃.     

CO2低温蒸发过程的热力分析与比较

通过对CO2与几种常用低温制冷剂蒸发过程的热力分析与比较，得出自然工质CO2亚临界循环具有明显的优势，应用于超市等商用制冷系统的低温循环，具有很好的应用前景。     

基于红外测温法的MOCVD工艺温度分析

为了得到MOCVD工艺生长过程中石墨盘的温度分布,提出了基于红外测温法的非接触无损测量方法,使用自主研发的双波长红外测量仪,能够得到石墨盘的径向和圆周温度分布情况,对MOCVD的加热炉结构改进和工艺过程控制有很大的指导意义。     

Comparison of Transfer Standard Industrial Lamps against PTB-assigned Radiance Temperature of Vacuum and Gas Filled Tungsten Strip Lamps

Accurate determination of temperature is one of the prime requirements in almost all the areas of physical metrology as it affects the process of any of the industrial manufacturing products. Planck’s equation serves the best approximation for determining temperature of a thermal radiating source. The ratio of pyrometric output signal due to intensities of two radiating sources can be utilized to measure temperature of an unknown source in terms of the temperature of reference metal freezing point source or a high stability tungsten strip lamp. The present paper provides an assessment of a set of tungsten lamps having strip or ribbon filament when compared against the emission of high stability standard lamps. The temperature measured in terms of electrical current across the lamp terminals has been estimated with an uncertainty reasonably acceptable for accurate determination of radiance temperature by these lamps. The uncertainty of temperature at each comparison point for lamps under assessment has been evaluated and reported. The best uncertainty of temperature was estimated to be ±1.7 K at 1073 K, ±1.5 K at 1273 K and ±3.7 K at 2473 K. The uncertainty at 1,073 K is higher as compared to at 1,273 K, is because of very low value of photocurrent signal produced due to low intensity observed at this temperature. The industrial strip lamps, compared against reference standard lamps serve as accurate sources of radiance temperature for comparing the disappearing filament Opto-spectral pyrometers used as direct temperature measuring instruments in the laboratories and in industries in the range above 1,073 K to as high as 2,500 K.     

衬底温度对ITO和ITO:Zr薄膜性能的影响

利用双靶共溅法在玻璃衬底上沉积了Zr掺杂ITO薄膜,对比研究了在不同衬底温度下ITO和ITOZr薄膜性能的变化.XRD和AFM分析表明,ITOZr比ITO薄膜具有更好的晶化程度和较低的表面粗糙度,Zr的掺入促进薄膜晶化的同时导致了(222)晶面向(400)晶面取向的转变.室温下Zr的掺杂显著改善了薄膜的光电性能,方阻由260.12 Ω降为91.65Ω,光学透过率也有所上升.随着温度的上升,方阻可达到10 Ω,薄膜也表现出明显的"B-M"效应,通过直接跃迁的模型得出ITOZr比ITO薄膜具有更宽的光学禁带.共溅法制备的ITOZr薄膜比传统的ITO薄膜展现了更好的综合性能.     

基于MEMS热电堆传感器的高温测量技术

为了拓宽MEMS热电堆传感器的温度测量范围,实现高温测量,根据MEMS热电堆传感器的原理,设计完成了A2TPM1334型MEMS热电堆传感器静、动态标定装置.通过试验得到标定结果;同时提供了基于MEMS热电堆传感器实现瞬态高温测试的技术方案及实现手段,并对其关键部分一红外衰减片性能进行了分析和讨论.     

基于声学法测温的声波飞渡时间研究

声波飞渡时间的准确测量是声学法测温中影响温度场测温准确性的主要因素。采用互相关分析法计算单一频率声波信号及宽带频率声波信号的声波飞渡时间,仿真结果表明宽带频率信号由于具有较强的抗噪能力在计算声波飞渡时间时不受声波信号周期、信号延时时间等因素的限制,可用于工程实践。同时采用频率为40kHz的正弦波超声波探测器在均匀温场条件下对超声波信号的衰减程度进行试验研究,试验结果表明40kHz的正弦波超声信号在不经过放大处理条件下,其可测温场的距离仅为160mm。