A new level detector for liquid nitrogen based on high-T_csuperconductors

Abstract

The authors have designed a level detector for liquid nitrogen, which is based on the use of high-Tc superconducting materials. Level detection is performed by resistance measurements of superconducting sensors. The transition temperature of the superconductors is set to a value slightly above the boiling point of the corresponding liquid. This is achieved by a partial replacement of barium by strontium in Y1Ba2Cu3O7-x. The authors discuss in more detail the set-up used to test the detectors.