介绍了作为干涉式红外光谱仪重要部件的分束器的作用。根据分束器装校后产生的面形峰-谷(Peak-to-Valley, PV)值变化量必须达到0.05λ(λ=632.8 nm)的要求。确定了分束器的支撑方式。通过对其在平放、竖放和失重情况下的面形变化进行有限元分析, 得知对压片施加不同的压强可以控制分束器的面形变化。发现在竖放时影响最大, 此时能施加的最大压强为0.866 MPa。通过分析, 为分束器选择了弹性支撑材料, 确定了其尺寸大小, 并将其加工成了实物。实际测量值证明, 通过有限元分析方法能充分满足分束器的高精度装校要求。这为提高系统的精度提供了依据。

The role of a beam splitter for an interference infrared spectrometer is presented. According to the requirement that the peak-to-valley (PV) value variation of a beam splitter should be 0.05 λ (λ=632.8 nm) after it is fixed, the supporting method of the beam splitter is determined. By analyzing the PV value variation of the beam splitter when it is in the states of flatness, verticality and zero-gravity by a finite element method, it is derived that the PV value variation of the beam splitter can be controlled by applying different pressure to the tablet used. It is found that when the beam splitter is in the state of verticality, its PV value is varied greatly and the maximum pressure which can be applied is 0.866 MPa. The elastic supporting material is selected, its size is determined and a supporting sample is made. The actual measurements show that the analysis by the finite element method can meet the high precision supporting requirement of the beam splitter fully. This provides the basis for the accuracy improvement of the instrument system.