Capacitance level sensor with integrated cold electronics

Capacitance type level sensors are extensively used for level measurement both for cryogenic and room temperature applications. The measurement of capacitance was carried out using various commercially available electronic circuits. All these circuits are designed to operate at room temperatures. A cold Electronics based level measurement circuit is designed which operates from 300 K down to 4.2 K. The frequency of the cold electronic oscillator is a function of the liquid level due to the change in capacitance value of the level sensor. The details of the calibration setup are discussed. Liquid Nitrogen was used as cryogen for the calibration. The details of developed cold electronics and its performances are discussed in this paper.