Ma Jiayu, Zhang Yuzhi, Wu Lingnan, Li Haogeng, Song Lixin
Key Laboratory of Inorganic Coating Materials CAS, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Materials (Basel). 2019 Apr 8;12(7):1141. doi: 10.3390/ma12071141.
Thermal control materials are employed to adjust the temperature of a spacecraft operating in deep space. The spectral emissivity is a crucial factor in evaluating the thermal radiative properties of such materials. An apparatus, composed of a Fourier transform infrared spectrometer (FTIR), a sample cooling chamber and a mechanical modulation system was demonstrated to measure low temperature infrared spectral emissivity under vacuum. The mechanical modulation system, which includes a chopper and a lock-in amplifier, is employed to reduce the interference of background radiation during measurements. The limitation of the Fourier transform frequency on the chopper frequency can be eliminated by setting the FTIR on step-scan mode. The apparatus is separated into two parts and evacuated by different pumps. In this study, a high quality emission spectrum of a sample is measured by the apparatus. The spectral emissivity of thermal control materials are obtained in the wavelength range of 8 to 14 μm at 173 and 213 K. The combined standard uncertainty of the apparatus is 3.30% at 213 K.
热控材料用于调节在深空运行的航天器的温度。光谱发射率是评估此类材料热辐射特性的关键因素。展示了一种由傅里叶变换红外光谱仪（FTIR）、样品冷却室和机械调制系统组成的装置，用于在真空下测量低温红外光谱发射率。机械调制系统包括一个斩波器和一个锁相放大器，用于在测量过程中减少背景辐射的干扰。通过将FTIR设置为步进扫描模式，可以消除傅里叶变换频率对斩波器频率的限制。该装置分为两部分，由不同的泵进行抽真空。在本研究中，用该装置测量了样品的高质量发射光谱。在173 K和213 K温度下，获得了热控材料在8至14μm波长范围内的光谱发射率。该装置在213 K时的合成标准不确定度为3.30%。
