Level gauge for liquid helium
US4655079A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1984 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Nov 21, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/842
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A level gauge for liquid helium comprising a sensing element in the form of a ribbon wire made of superconductive alloys and a tube supporting the sensing element, which tube is inserted into liquid helium upon measurement. The superconductive alloys are represented by a formula Zr.sub.100-x.(Ru.sub.y.Rh.sub.1-y).sub.x in which x represents contents of Ru and/or Rh in atomic % and in a numerical value of 22.5.ltoreq.x.ltoreq.27.5 and y represents a numerical value of 0.ltoreq.y.ltoreq.1. The alloys are made of an amorphous phase obtained by rapid quenching a molten alloy material and have a superconducting transition temperature, Tc, of 4.2.degree. to 4.5.degree. K. When the level gauge is immersed in liquid helium, a portion of the sensing element below the level of the liquid helium has a zero electric resistance because of the superconductivity of the alloy, so that the level of the liquid helium can be detected by a variation in resistance of the sensing element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.