Thermoresistive Level Sensor for Cryogenic Liquids on the Basis of High-Temperature Superconductor

The employment of cryogenic and common capacitive equipment requires a continuous control of liquid line which can be performed, for example, with the help of thermoresistive sensors. These sensors are very sensitive, very reliable and compact, there are no mobile mechanical parts inside, they work at a direct current and they have no jet resistance that defines their high operational efficiency. The article provides the research results of thermoresistive sensors based on high-temperature superconductors as a sensitive element of the device for measurement the level of cryogenic liquids. The basis of such sensitive element is the lengthy composite conductor with a beryllium phase and a silver matrix. Such conductors are highly stable, of small thermal inertia and they have a good reproducibility of readings. In the case of obtaining volt-linear characteristics of prototypes of such sensors it was necessary to carry out an analytical research on a physical and mathematical model and a pilot study. A test bench was created in order to carry out the pilot studies and to remove volt-linear characteristics of level thermoresistive sensors. Pilot studies results were compared with modeling results thus allowing to reveal major factors that influence sensors properties based on high-temperature superconductors. The received volt-linear characteristics were used as the calibration curves during the creation of a device prototype for level measurement of liquid nitrogen. Comparison of settlement and experimental data for skilled sensors based on high-temperature superconductors allowed to determine the accuracy of settlement model which, for example an experiment sensor, didn’t exceed 13.5% in all the range of measurements.

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