Aspects regarding the liquid level measurement for a cryogenic pump

This paper outlines a method of continuous and direct level measurement of cryogenic fluid applicable to a completely immersed cryogenic pump. There are many industrial and scientific processes requiring the knowledge of liquid level in various devices useful for special applications. A particularly case is given by the need of pumping cryogenic liquid from different Dewar vessels with separate locations, as for example at different levels in a building, where a continuous pumping is necessary to cool large conducting cables or large cryogenic installations with forced flow. Ensuring an optimum performance of the cryogenic pump is directly related to the need of measuring the liquid level. In this work a technical solution and its suitability for liquid nitrogen services is presented, together with the proper automation system.