An Optical Periscope Technique for Measuring Cryogenic Liquid Level Height in Adverse Environment

摘要

A few of techniques for measuring liquid level height have been reported currently, such as ultrasonic measurement, capacitance measurement, and laser measurement, but in adverse environment of violent vibration, extreme low temperature liquid with high evaporation above the liquid surface, and explosion proof without allowance of electricity, none of the above techniques can be used. In this paper, a technique of optical fibers with periscope structure is proposed and used. In the experiments, liquid nitrogen has been employed to test the optical system, the height of over 1 m and the measurement accuracy of 1mm have been obtained.