纺织面料红外发射率测量的新装置及方法

New Device and Method for Infrared Emissivity Measurement of Textile Fabrics

针对现有红外发射率测量技术不适用于测量多孔质非良导体的纺织面料的情况,提出一种新的红外发射率测量装置及方法,即将反射率法中外部辐射热源与量热法的算法相结合。使用光热源正面辐射加热代替传统量热法中的热板背面加热,将面料背面紧贴于绝热材料上使之单向绝热,则背面温度计所测量的温度等于面料正面的真实温度,结合红外热像仪正面所测量的面料辐射温度,即可满足量热法计算公式的条件。使用两个外光热辐射源以60°夹角进行加热,可最大程度避免因产生透射热辐射而造成对背面温度计测量结果的影响,同时减少面料表面反射热辐射对面料辐射温度测量的影响,保证了面料红外发射率的测量准确性。试验结果表明,纺织面料的红外发射率基本都在0.8左右,个别超过0.9。参考物的试验结果亦证明该方法可用于其他类灰体的测量。

In view of the fact that the existing infrared emissivity measurement technology is not suitable for measuring textile fabrics with porous non-good conductors,this paper proposed a new infrared emissivity measuring device and method.That s combining the external radiation heating source in the reflectance method with the calorimetric algorithm.Heating in the front of fabric with photothermal radiation sources was adopted instead of heating in the back of fabric with a hot plate which was widely used in the traditional calorimetric method.The back of the fabric was attached to an insulation material to make it insulated unilaterally,so that the measured temperature of the back was equal to the true one of the front.Thus the true temperature of the fabric surface was obtained.The radiation temperature of the fabric was measured by an infrared thermal imager setting directly ahead of the fabric.After obtaining the two results,the calorimetric algorithm formula could be used.At the same time,in the new heating method,two external light and heat radiation sources were set in the angle of 60° to avoid the influence of the transmission heat radiation on the thermometer placed on the back of the fabric to the greatest extent.It also reduced the influence of reflection heat radiation on the measurement of radiation temperature of fabrics and ensures the accuracy of measurement of infrared emissivity of fabrics.The testing results show that the majority of the fabric infrared emissivity is around 0.8,while individual ones exceeds 0.9.The test of reference material also proves that this method could be used to measure other gray bodies.