Characterisation and stability of low-emittance multiple coatings for glazing applications

We present experimental studies on the deposition and characterisation of ZnS/Ag/ZnS low-e coatings carried out to assess their optical performance and stability. Theoretical predictions of the coatings optical properties were combined with measured emissivity () values to derive a figure of merit (η) defined as the ratio of luminous transmittance over emissivity. A coating consisting of 37.0 nm ZnS/21.5 nm Ag/37.0 nm ZnS was found to maximise η. Long-term experiments on the produced ZnS/Ag/ZnS coatings, under solar irradiation have revealed that a moderate vacuum (10⁻²–10⁻³ mbar) is required to avoid degradation of the film properties. Four-layer ZnS/Al/Ag/ZnS and five-layer ZnS/Ag/ZnS/Ag/ZnS coatings were produced and tested for thermal stability. They were both found to withstand heating at 300°C for 3 h. The four-layer structures however, present low transmittance in the visible, due to absorption by the Al layer.     

发射率和温度同时测定的辐射测温仪

提出一种新的不依赖发射率变化的辐射测温技术，它利用红外源作为参考光源，求得辐射体的发射系数后，进而实现不依赖于发射率变化的真实温度的测定。     

Wafer emissivity independent temperature measurements

A study on the techniques to yield wafer emissivity independent temperature measurements in rapid thermal processing has been presented. This study focuses on the Steag-AST Electronik approach to enhance wafer emissivity by using the Hotliner*. The Hotliner comprises of a heavily doped p-Si substrate sandwiched with Si₃N₄/SiO₂ from both sides. Experimental measurements on the optical properties of the Hotliner using a spectral emissometer operating in the wavelength range of 1–20 μm are presented here. Results of the simulation of the experimental data using the MIT/SEMATECH Multi-Rad model are discussed. Hotliner is a trademark of Steag-AST Electronik, patent pending.     

Application of dual-wavelength radiation thermometry to the aluminum industry

The objectives of this paper are to introduce the basic principles of dual-wavelength radiation thermometry, to show their utility in inferring temperature, and to investigate the influences of time-at-temperature and temperature on the emissivity behavior of selected aluminum alloys in their processing conditions. Thirteen algorithms are mentioned in this paper, and the results from six of them are reported. Experimental procedures and apparatus are described. The emissivity behavior as a function of time correlated fairly well with the results of Cochran and Sleppy. The ISS algorithm is capable of inferring temperature to within ± 1.6 K. Thus, it is recommended that the ISS algorithm be used for measuring the temperature of 5052 aluminum alloy extruded samples.     

基于前置反射器的多波长铸坯表面测温方法

钢铁冶金现场的连铸铸坯表面温度是重要的工艺参数,针对铸坯表面温度难以测量,研究一种前置反射器与多波长结合红外辐射测温方法,该方法分别建立有反射器和无反射器的多波长辐射能量方程,在线求解被测铸坯表面的发射率和铸坯表面温度。利用蒙特卡洛方法建立铸坯表面的多层模型和光波的多次反射-吸收的仿真模型,模型分析表明该方法可实现准确的铸坯表面温度测量。     

Variable emissivity infrared electrochromic device based on polyaniline conducting polymer

The use of polyaniline (PANI) as active layer in the electrochromic (EC) devices operating in the mid-infrared (mid-IR) ranges (3–5 μm, 8–12 μm) was investigated. The optical properties of the device were characterized by spectrophotometry in the wavelength range from 0.4 μm to 15 μm. Results show that upon reversible doping and undoping, the devices yield an average emissivity dynamic range of ca. 0.24 in the 8–12 μm region. The lowest emissivity of the devices in this region can be adjusted from 0.4 to 0.68 according to the preparation conditions. The average reflectance dynamic range is 18% in the 3–5 μm and 34% in the 8–12 μm regions.     

A compilation of data on the radiant emissivity of some materials at high temperatures

This paper gives a compilation of experimental data from a variety of sources of the emissivity of materials used in high temperature applications. The data is given in the form of temperature dependent correlation equations which can be used for modelling purposes. The data on refractory materials show the importance of surface properties, the effect of surface coatings and ways in which these can be taken into account for more accurate predictions of emissivity. Information is also given on chars, ash particles and furnace deposits resulting from the combustion of coal and biomass.     

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.     

发射率的修正在红外校准工作中的应用

在红外温度计的校准工作中,发射率对校准结果有很大的影响,文章立足于实际应用,从黑体辐射源和红外温度计两个方面归纳总结出了因发射率的偏差B1人的温度计示值的修正方式。     

红外涂料对通电电阻带工况的影响

对通电电阻带在喷与不喷涂料两种工况进行实验研究，得出：将喷涂了红外涂料的电阻带应用于各种高温生产系统及高温运行的设备可，可达有效节能，提高设备寿命的目的。