LHE level detector for superconducting generators, operating performance at constant voltage or constant current supply

Level detection usually is done with superconducting level sensors, with carbon resistors or with semiconductor devices. Each type of sensor alters its output whether it dips into liquid helium or not. The simple level detection is disturbed by several environmental effects as there are pressure gradients in the liquid or magnetic fields. For that reason the signal difference between liquid and gas sensing should be as distinct as possible. The paper reports some considerations on carbon resistor type level sensor intended for use in a superconducting rotor