A new directional polarized spectral emissivity measurement apparatus with the wavelength range of 4–20 μm was established to promote the development of thermal radiation transfer and polarization engineering. The measurement accuracy was improved by eliminating the background radiation with a high emissive thermostatic shutter and precisely determining the sample surface temperature. An accurate expression for directional polarized spectral emissivity was obtained taking into account the multiple reflection between the sample and the chamber. The linearity of spectral response was calibrated respectively in parallel and perpendicular polarized directions. The directional polarized spectral emissivity of a high-purity SiC sample was measured in a controlled environment to validate the capability of the apparatus. The excellent agreement between the measurement result and the literature data proved the reliability of the experiment apparatus and the measurement method. The measurement uncertainty was evaluated for each experiment, and the relative uncertainty was estimated to be less than 4.1%.

为了促进热辐射传输和极化工程技术的发展，建立了一种新型的定向极化光谱发射率测量仪器，其波长范围为4–20μm。通过使用高辐射恒温快门消除背景辐射并精确确定样品表面温度，提高了测量精度。考虑到样品和腔室之间的多次反射，获得了定向偏振光谱发射率的精确表达式。分别在平行和垂直极化方向上校准光谱响应的线性。在受控环境中测量了高纯度SiC样品的定向偏振光谱发射率，以验证该设备的功能。测量结果与文献数据之间的优异一致性证明了该实验装置和测量方法的可靠性。对每个实验评估了测量不确定度，估计相对不确定度小于4.1％。