LUO Li, YANG Yonggang, HU Wentao, LIN Jiaben
The multi-channel birefringent filter, which is designed to improve the ability to observe the monochromatic property of the sun, is regarded as an important instrument for solar magnetic field observation. The refractive index of the birefringent crystal in the optical filter issensitive to temperature. Therefore, it is necessary to control constant temperature. Measuring temperature is premise of constant temperature control. A high-precision temperature measurement system based on Pt100 is studied and designed. The principle of high-precision temperature measurement, the circuit of temperature acquisition system and the scheme of temperature correction are provided.Finally, the high-precision temperature measurement instruments, such as RR9710, TD-1,are used to calibrate accuracy indirectly. The test results show that the temperature measurement system is stable and efficient.The accuracy could be reached to 0.02 ℃.