NMR circuit-switch
US5982179A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1997 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Jun 4, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3635
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A 1/4 wave circuit switch for use in an NMR probe has a housing with a stepped cavity for precisely locating switch components inside. The 1/4 wave circuit switch cooperates with a 1/4 wave tube and is designed to receive either an external capacitor on a capacitor stick for single tune operations or a 1/4 wave center conductor with a threaded tip on a 1/4 wave stick for double tune operations. For single tune operations, the external capacitor comes into contact at one end with a resiliently supported, movable electrical contact and at the other end with a spring clip inside the housing cavity to orient the external capacitor in parallel with the NMR coil. The movable electrical contact is resiliently biased by a pair of crescent washers supported by an insert plug which serves as a positive stop for the travel of the electrical contact. For double tune operations, the threaded tip of the 1/4 wave center conductor simultaneously contacts a pair of threaded contacts provided inside the housing cavity and spaced by an insulating spacer. The simultaneous contact creates a current path which grounds the NMR circuit through the 1/4 wave tube, so that the NMR circuit may resonate at two…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.