金属熔点温度和法向光谱发射率数据是国际上对电流脉冲加热技术测量材料热物性参数的关键比对点。针对连续测量金属熔点附近温度的特点,提出了一种新的发射率假设模型,并在此基础上提出了一种新的多光谱高速高温计的数据处理方法。该方法只需使用多光谱高速高温计作为测量装置,通过处理两个不同时刻多光谱高速高温计的测量数据,由计算可同时获知两个时刻的真温及光谱发射率。经对国外的标准铌试样进行了测试,所得数据与国外同行的测量数据进行了比对,具有较好的一致性,实验结果表明,熔点真温计算值与生产者提供的值之差在±20K以内。
Temperature and normal spectral emissivities of melting point are considered one of the most important values for the measurement of thermophysical properties at high temperatures. Considering the characteristics of the plume temperature measurement of melting point, a new emissivity assumption was presented. Based on the assumption, a new data processing method of multispectral pyrometer was introduced. The normal spectral emissivity and true temperature of the strip meltal specimen at the melting point was measured only by multispectral pyrometer. By processing the measured data of the multispectral pyrometer at two different time, the true temperature and spectral emissivities at two different time can be simultaneously calculated. A kind of international standard niobium specimen was measured. The results were compared with literature data obtained in pulse-heating experiments. The experimental results show that the temperature differences between the calculated values and the ones provided by designer are within ± 20K.