To verify the performance of refractive index of air measurement system,which has a great influence for accuracy of laser interferometer,one kind of calibration approach is presented for the refractive index of air measurement system of laser interferometer. One special calibration setup is designed which consists of temperature,air pressure and humidity sensors and it is based on Edlén formula to measure the refractive index of air indirectly. Experiment shows that the temperature uncertainty is less than 0. 02℃ in(5~40)℃,uncertainty of air pressure is 18 Pa in(60~110)kPa and uncertainty of air humidity is 2. 0% RH in(10~90)%RH. The relative expend uncertainty of whole system for refractive index of air is 1 × 10-7 ,where cover factor k=2.%为了检验对激光干涉仪测量精度有很大影响的空气折射率测量系统的测试性能，提出一种可用于基于Edlén公式的空气折射率测量系统的校准方法，并且设计了专门的校准装置，该装置主要由温度、气压以及湿度测量系统组成。实验证明：取包含因子k=2时，温度在（5~40）℃区间，测量不确定度U优于0.02℃；气压在（66~105）kPa区间，U=18 Pa；湿度在（10~90）%RH区间，U=2.0%RH，等效于整个系统对应的空气折射率测量的相对不确定度优于1×10-7。
展开▼
