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。     

精密黑体辐射源标准装置设计研究

为了解决辐射温度计的检定、校准中因黑体辐射源发射率低问题而引入的修正问题,文章设计了温度范围为-10~110℃的精密黑体辐射源。在等温条件下,利用基于光线跟踪技术的Monte Carlo方法对黑体空腔法向有效发射率进行了计算,结果表明,设计的精密黑体辐射源理论法向有效发射率不低于0.999 2。     

发射率影响修正近似公式及其适用性分析

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.     

黑体辐射源的多波长有效亮度温度校准和不同溯源方式特点分析

介绍了中国计量科学研究院建立的标准变温黑体辐射源和有效亮度温度比较装置;阐述了黑体辐射源多波长有效亮度温度校准的2种方法,给出典型校准结果并分析了辐射源特性。比较分析了3种溯源方式的性能特点及其应用的影响因素。提出控温复现性的概念,它是以往未被重视的辐射源关键性能参数。多波长有效亮度温度校准是可减小或消除有效发射率和接触测温测点温差影响的溯源方案,与传统溯源方式特性互补,可用于评价辐射源的有效发射率和测点温差,对控温复现性好的辐射源效果最优。     

发射率设定值不为1的辐射温度计的校准

分析了用黑体辐射源校准发射率设定值小于1的辐射温度计时,对温度计示值的影响,介绍了近似修正方法及典型计算结果.     

耳温计检定校准用黑体空腔有效发射率比较与亮度温度比对实验

耳温计检定校准用黑体辐射源是耳温计检定和校准的计量标准器,黑体空腔的有效发射率是其关键特性。介绍耳温计检定规程推荐黑体空腔的发射率特性,并与两种国际标准推荐的耳温计黑体空腔进行了亮度温度比对实验。在数据分析基础上,给出对三个耳温计黑体空腔的评价。     

基于VBA实现黑体辐射源发射率偏离1引起有效亮度温度修正

按照最新的工作用辐射温度计检定规程和辐射测温用-10～200℃黑体辐射源校准规范要求,需要根据有效亮度温度概念,通过对黑体辐射源进行发射率影响修正和环境辐射误差修正,文章对有效亮度温度发射率影响数学模型,使用VBA语言,研究二分算法,高效实现有效亮度温度与实际温度的修正计算,从而为日常检定、校准工作提供了有力的技术保障。     

黑体辐射源发射率对辐射测温准确度的影响及修正方法

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.     

200 ℃以下红外温度计校准的相关研究

研制了一种可用于200 ℃以下的红外温度计校准的标准黑体辐射源。应用3种不同方法的计算,得到的黑体空腔的有效发射率均在0.997以上。通过一系列的试验,得出工作距离与环境温度是2个重要影响因素,给出了校准中的最佳工作距离,并指出保持温度计环境温度恒定的重要性。     

氟利昂热管黑体辐射源性能实验研究

为了满足机场、车站等红外筛检仪器辐射温度现场校准的要求,文章介绍了一种氟利昂热管黑体辐射源。黑体辐射源空腔形状为圆柱-圆锥形,空腔长100 mm,锥角为120腔,法向平均有效发射率计算值为0.995。利用TRT2辐射温度计对黑体辐射源腔底进行辐射温度测量,对热管进行不同角度的倾斜,测得的黑体辐射源温度稳定性优于0.2℃,氟利昂热管空腔内均匀性优于0.2℃,可以满足现场校准需求。     

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.     

An Oil-Bath-Based 293 K to 473 K Blackbody Source

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.     

A Third Generation Water Bath Based Blackbody Source

A third generation water 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 improved temporal stability and reproducibility compared with earlier designs, as well as improved ease of use. These blackbody sources operate in the 278 K to 353 K range with water temperature combined standard uncertainties of 3.5 mK to 7.8 mK. The calculated emissivity of these sources is 0.9997 with a relative standard uncertainty of 0.0003. With a 50 mm limiting aperture at the cavity; entrance, the emissivity increases to 0.99997.     

检定原子荧光光度计常见问题分析

提出了原子荧光光度计检定过程中可能出现的常见问题。根据经验和仪器的工作原理对问题产生的原因进行了分析,并针对不同问题给出了具体的解决措施。对实现检定结果的准确可靠具有较好的保证作用。     

固定发射率工作用辐射温度计校准方法研究

讨论分析了用于校准固定发射率工作用辐射温度计的原理。在校准中,应用辐射面源是必要的,其发射率应与温度计的固定发射率一致,以保证温度量值传递的准确性,并分析了由于两个发射率的不一致而带来的温度误差,给出了在不同温度下由发射率偏离而引起的温度误差计算式。在发射率为0.95、温度为700 K的情况下,最大误差可以达到15 K。如果实际测量对象的发射率与温度计的固定发射率相同,则可以直接测量出被测对象的真实温度。     

直流稳流电源输出纹波和噪声的测试方法

如何准确测量出直流稳流电源输出纹波和噪声是电源检定/校准工作中需要解决的问题。通过具体事例分析了用不同的测量设备测量同一台电源的纹波电压其结果不同的原因,提出了在测量稳流电源的纹波电压的过程中如何选择负载类型,为实际电源纹波测量工作提供了一些参考。     

动态温度测量与校准技术

尽管动态温度测量技术得到了快速发展,但由于动态温度测量既与传感器本身结构相关,也与所处工况相关,影响因素众多,因此动态温度的测量仍然难以满足实际的需求。本文对国内外的动态温度测量与校准技术分别进行了介绍,分析了温度传感器动态特性校准的特点,并在此基础上提出动态温度测量与校准技术的发展方向。     

红外耳温计分度方法及数据分析

研制了一种专门用于红外耳温计分度的双孔黑体空腔,并用研制的黑体空腔对红外耳温计在37℃和41℃进行了分度实验.实验结果表明,此黑体空腔的空腔发射率已达到0.999,完全能作为红外耳温计分度的标准辐射源.最后对实验结果进行了不确定度的评定.     

双级气流场压力解耦控制研究

针对温度、压力、湿度多参数复合计量检定装置中双温双压法湿度发生的上级饱和气体压力和下级实验舱气体压力控制具有强耦合关系,提出了一种基于对角矩阵的双极气流场解耦方法。该方法利用理想气体状态方程和调节阀流量特性建立双输入双输出气流场控制模型,运用对角矩阵法将原系统变为两个独立的单输入单输出控制系统,消除两者之间的耦合关系。实验结果表明:该方法取得了很好的效果,饱和器和实验舱的压力控制稳态精度都得到大幅度提高。     

Development of a New InGaAs Radiation Thermometer at NMIJ

The first InGaAs radiation thermometer at NMIJ was developed more than ten years ago as a standard radiation thermometer operating from 150 to 1,100°C. Its size-of-source effect (SSE) was as large as 1% from 6 mm in diameter to 50 mm in diameter. The new thermometer has an SSE of 0.3%. The reason for the error in measuring the SSE of InGaAs thermometers was also found. The new thermometer at first suffered from nonlinearity and the distance effect (DE). These deficiencies arose from the misalignment of optics inside the thermometer and were solved by increasing the detector size from 1 mm in diameter to 2 mm in diameter. Unfortunately, the detector of 2 mm diameter had a smaller S/N ratio than that of the 1 mm one at the indium (In) point. The final design uses a detector of 1 mm diameter, but the radiation is focussed on a smaller area of the detector. The new thermometer is smaller and lighter than preceding designs and other standard InGaAs radiation thermometers. The temperature of the main part of the instrument, including the filter, the detector, and the preamplifier board, is controlled at 30°C. In addition to the calibration with the six fixed points of copper (Cu), silver (Ag), aluminum (Al), zinc (Zn), tin (Sn), and indium (In), the linearity from the In point to the Cu point, the SSE, the DE, and the spectral responsivity were measured.