Magneto-optic current sensor having a mechanically stress-free .lambda./4 element
US5953121A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Dec 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Without special measures, a fiber-optic current sensor coil (11) and fiber-optic .lambda./4 time delay elements (9, 9'), which are connected in series with the current sensor coil (11), are temperature-dependent with respect to a relative phase lag of light passing through. In order to avoid a temperature correction or temperature compensation, the current sensor coils (11) and, if appropriate, also the .lambda./4 time delay elements (9, 9') are annealed, so that virtually no mechanical stresses remain in the optical fibers. The current sensor coil (11) is preferably mounted unrestrained in a capillary (20) filled with a protective gas. The capillary (20) is embedded in a gastight fashion in a potting compound (22) made from polyurethane, and is thus also mechanically protected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.