The Study Of Low Thermometer Calibration System

Cryocondensation pump is an important component in neutral beam injector. During the course of downing temperature and keeping temperature and returning temperature, Temperature should be accurately monitored. Temperature measure accurately is related to the neutral beam injection technology diagnose. So we develop an applicative low thermometer calibration system.The five thermometers can be calibrated at a time in a calibration experiment. All thermometers are mounted on an isothermal copper block hunting in a vacuum vessel and thermally insulated. The temperature is stabilized by means of a proportional integral regulator in low-temperature controller which controls a resistance heater mounted in copper block. The thermometers are calibrated within the temperature range 3.8 K to 300 K.The cryostat is an important component in calibration system applicative low thermometer calibration system. And simulate the constant-temperature block temperature distribution in the cryostat by the software of Origin 6.1. The calibration system components of cryostat and constant-current-source and low-thermometer controller have been made an performance experiment and analysis actual factor of influence calibration system accuracy that is 45.441 mK under the temperature 20 K,which reaches our anticipated intention. And it is proved that the calibration system is reliable. And the calibration system also can calibrate other thermometers.