Methodology for spectral emissivity measurement by means of single color pyrometer

The application of non-intrusive optical devices, such as infrared pyrometers able to measure the temperature of surfaces, makes possible the evaluation of emissivity curve of the tested materials at different temperature values. In this paper the authors propose a methodology for the spectral emissivity measurement by means of a single color pyrometer providing a semi-empirical formula, obtained experimentally at CIRA’s laboratory. The semi-empirical formula allows to know the actual emissivity value of the sample’s surface for whatever emissivity value set up on the pyrometer. The agreement between the experimental emissivity and the emissivity predicted by semi-empirical formula was verified.     

热电偶配用补偿导线测温误差分析及修正方法

本文根据热电偶配用补偿导线测温原理,进行了测温误差分析,并用计算机程序计算得到了实用镍铬－镍硅热电偶配用铜－康铜补偿导线的测温误差修正表。     

Simultaneous measurement of emissivity and temperature of silicon wafers using a polarization technique

The emissivity of a silicon wafer under various conditions was theoretically and experimentally investigated. A quantitative relationship between the ratio of p-polarized to s-polarized radiances, and the polarized emissivity was obtained, irrespective of the emissivity change of silicon wafers due to oxide film thickness under wide variations of impurity concentration. We propose a new radiation thermometry method that can measure both the temperature and the spectral polarized emissivity of a silicon wafer, and we estimate the uncertainty of these measurements. Currently, the expanded uncertainty of the temperature measurement is estimated to be 3.52 K (2k) and 3.80 (2k) for p-polarization and s-polarization, respectively, at temperatures above 900 K.     

利用MAX6675组建测温网络

分析了集成温度传感器的应用局限性以及常用热电偶和热电阻测温系统的缺陷,提出了用高度集成的热电偶信号处理芯片MAX6675组建测温网络（系统）的优越性。介绍了MAX6675的工作原理及特点,并给出了基于MSP430单片机测温网络的硬件实现和软件设计。     

Application of multispectral radiation thermometry in temperature measurement of thermal barrier coated surfaces

Ceramics coatings are materials widely used in gas turbines to provide thermal shielding of superalloy materials against excessive turbine temperatures. However, measurement of their surface temperatures using conventional radiation thermometers, more so in the presence of high ambient radiation and low emissivity is quite challenging. A multispectral method employing curve fitting technique to measure the temperature of such targets in the range of 800–1200 K and ambient temperature of 1273 K is implemented in this paper through simulation. Several simulated experiments were carried out to identify emissivity models best suited for multispectral radiation thermometry applicable to ceramic coatings. The best emissivity model applicable to yttria-stabilized zirconia of coating thickness of 330 μm in the wavelength range of 3.5–3.9 μm was found to predict temperature with an error of less than 1.5% in the presence and absence of background noise.     

Non-contact temperature measurement of silicon wafers based on the combined use of transmittance and radiance

We propose a non-contact temperature measurement method that combines the temperature dependence of transmittance below 600 °C and radiation thermometry above 600 °C. The combined method uses a polarization technique and the Brewster angle between air and a dielectric film such as SiO₂ or Si₃N₄ grown on silicon wafers. A prominent feature of this method is that both measurements of transmittance and radiance are performed with the same geometrical arrangement.For a semitransparent wafer, the measurement of p-polarized transmittance at the wavelengths of 1.1, 1.2 and 1.3 μm enables temperature measurement in the range from room temperature to 600 °C. For an opaque wafer above 600 °C, the p-polarized radiation thermometry at the wavelength of 4.5 μm allows the temperature measurement without the emissivity problem. The combined method with the use of transmittance and radiance is valid in the entire temperature range irrespective of variations of film thickness and resistivity.     

光纤双波长数字式测温仪系统研究

本文系统地介绍了一种双波长光纤测温仪的原理、结构及特点,其突出优点有：采用双波长窄带比较技术和以微控制器,可编程外围芯片为核心,构成数字化、小型化光纤传感系统,抗干扰能力强,具有通信接口,可与过程控制网络连接,支持流行的现场总线协     

航空发动机全流程参数试验中温度和压力测量综述

航空发动机全流程参数测量是发动机研制阶段的重要环节,是全面了解发动机性能的唯一手段。国内外各大发动机研究机构和工厂对此都非常重视并相当保密。对国内外航空发动机全流程参数测量发展状况进行了介绍,主要对试验中发动机温度和压力的测量技术进行了归纳和分析。     

Voltage divider resistance for high-resolution of the thermistor temperature measurement

When measuring temperature with a voltage divider, and changing the variation of the thermistor resistance from the temperature to the voltage, the divider resistance greatly impacts the resolution of each ADC step. This work presents a method for determining the divider resistance to minimize the resolution’s maximum value in a given temperature range. Since the function of the resolution strongly depends on the derivative of the thermistor resistance, we also investigated the effect on the resolution when the derivative was calculated by forward and backward finite differences and the Stein–Hart calibration equation. The results showed that the resolution’s maximum calculated by the three methods had only a 5% difference, for the four types of commonly used NTC thermistors. Also, we demonstrated that the divider resistance which minimizes the interval resolution’s maximum can be determined by the thermistor resistance and its derivative at each end of the temperature range.     

Pyrometric temperature measurement of ceramic thermal shock samples

The determination of critical failure parameters during thermal shock requires a time and space resolved temperature measurement of the sample. High frequency pyrometry is a suitable technique for such a measurement task, which usually requires the knowledge of the optical properties of the investigated material. Another challenge is the infrared transparency of materials to be checked in the wavelength range of the pyrometer. The thermal shock disks are very thin, due to the need of homogeneous temperature distribution and to maintain a two-dimensional problem. To allow a pyrometric temperature measurement a universal calibration method for high frequency infrared cameras has been developed. Pyrometry in various media was demanded, as well as the estimation of optical properties (reflection, transmittance and emission) for the selected ceramics to be tested.     

Ultrasonic tomography based temperature distribution measurement method

The temperature distribution information plays an important role in industrial applications. Owing to the advantages such as non-intrusive sensing and low cost, the ultrasonic tomography (UT) is considered to be a promising method for temperature field visualization. The ultrasonic time-of-flight (TOF) measurement and the reconstruction algorithm are crucial for practical applications of the UT measurement. In this paper, a dual-threshold measurement method is proposed to ensure a high-quality TOF measurement. In view of the inaccurate nature of the reconstruction model and TOF data, a new reconstruction method that integrates the advantages of the Tikhonov regularization method and the least squares support vector machine (LSSVM) is proposed to improve the reconstruction quality. The experimental results were compared against thermocouple measurements and the results show that the temperature distribution can be reconstructed with the error of 1.3%, which validates the feasibility and effectiveness of the proposed Tikhonov-LSSVM reconstruction algorithm.     

Industrial low cost temperature measurement in permanent electro-magnetic platens

In automatic production controls a fully knowledge of all the state of the different system is often mandatory. In particular the measurement of many parameters is necessary in order to obtain the desired specification in terms of both safety requirements and protective measures for operator’s safety and in terms of system reliability in compliance with both the international standards and the correct working conditions. In the field of Injection Moulding Machine (IMM) the European Standard EN201 is the reference standard. In particular, the mentioned standard specifies “the essential safety requirements for injection moulding machines for the processing of plastics and/or rubber” and “the safety requirements for the interaction between injection moulding machines and ancillary equipment”. If a magnetic clamping system is used in order to attach the mould to the platens the measure of the temperature of permanent-electro magnetic platens is mandatory. In this paper, after a brief introduction concerning the theory of operation of the permanent-electro magnetic platens, an example of industrial low-cost temperature measurement for permanent-electro magnetic platens is presented and discussed in each aspect. At this aim a theoretical introduction has been presented, and in a second time, actual implementation of the proposed approach is finally depicted and discussed.     

Roughness form and waviness measurement by means of light-scattering

This paper deals with a non-contact, optical measuring method which unites the assessment of roughness form and waviness in one single instrument. The     

长光栅旋转测角法的研究

本文介绍了一种长光栅副相对旋转测角的新技术。建立在付立叶光学理论基础上的分析与实验结果是一致的。采用本方法与现代微机技术相结合,可以用非常简单的结构实现对小角度的高精度测量。仪器测量范围为±30′,测量精度为±0.5″。     

编解码电路在温度测控系统中的应用

本文介绍一种用编码、解码集成电路进行多点温度测控的系统。文章首先介绍编解码电路ＳＹ８０８Ｅ／Ｄ,然后给出温度测控系统的硬件电路及软件框图。     

Experimental mathematical model as a generalization of sensitivity analysis of high temperature spectral emissivity measurement method

The development of an experimental mathematical model describing temperature state of the sample during high temperature spectral emissivity measurement is introduced. Dimensional analysis of the measurement process gives the physical dimensionless quantities and sensitivity analysis of the measurement process provides the large set of performed model experiments. Evaluated experimental mathematical models are presented including their accordance with model experiments. Established equations are generalization of sensitivity analysis of high temperature spectral emissivity measurement method and can be used for computation of spectral emissivity total uncertainty.     

超声物位检测系统中的误差来源及补偿方法

本文阐述了超声波物位测量技术中影响测量精度的因素．对造成测量误差的原因——进行了分析，并且讨论了相应的补偿方法。     

Wireless sensor marking and temperature measurement with SAW-identification tags

A wireless sensor marking system based on surface acoustic wave (SAW) identification tags is presented. The proposed solution is compatible with existing measurement systems and can be applied directly in the sensor or by means of a unique sensor identification cable (SIC). The SAW tag operates completely passive, and withstands temperatures up to 400 °C as well as shocks up to 35 000 m/s². It contains a unique serial identification number, which is encoded on the high-temperature stable SAW device by means of metallic reflector gratings. The interrogation unit uses the sensor cable for transmission but is not directly connected to it, thus the identification system can be even used with high impedance measurement equipment, e.g. charge amplifiers. Interrogation is done in frequency-domain based on well-known radar principles and is realized in a low-cost add-on circuit to the existing sensor evaluation circuitry. Furthermore, by simply enhancing the evaluation software, a temperature measurement of the SAW tag itself, and thus often of the sensor or the sensor environment can be done without additional hardware requirements.     

Optimization of experimental temperature measurement in GTAW process by means of DoE technique and computational modeling

The prediction of temperature distribution is a critical process in the study of welding thermal field. Therefore, the accuracy in temperature measurement is quite important to provide meaningful results and to establish the coupling among thermal field results and other studies in welding as mechanical and microstructural analyses. This work deals with statistical analysis and design of experiments (DoE) in order to establish an optimal experimental design for thermal history measurements in welding processes with thermocouples independent of base material. Calculations from theoretical correlations and computational modeling of heat flow were used to accomplish the present study. The Gas Tungsten Arc Welding process (GTAW) was used in the experiments along with plates of a structural steel (ASTM A 36) and a martensitic stainless steel (AISI CrMo 12-1). Four different parameters were studied related with the disposition, separation, depth, thermocouple arrangement and application of thermal paste. An optimal design was able to measure the maximum temperatures in adjacent zones to the weld bead, which are important for the study of welding thermal behavior.     

锥形内表面干涉测量误差分析

为了实现对回转锥形内表面的形貌精密测量,分析了干涉测量中误差产生的原因,明确了误差对测量结果造成的影响。通过在圆柱坐标系下建立数学模型,推导出偏移误差和角度误差的数学公式,并对误差公式进行分析。结果表明:圆锥反射镜的偏移量和顶角的加工误差都会造成光程差;当偏移量极小时,光程差与反射镜偏移量成线性关系;光程差对于角度误差非常敏感,为了保证测量精度,需要严格控制圆锥反射镜的顶角大小。