Strain measuring device employing magnetostriction and having a magnetic shielding layer
US5022275A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1989 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Apr 12, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/872
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a strain measuring device employing a magnetic permeability detector means to detect an amount of strain in a passive member as changes of magnetic permeability in a magnetostrictive layer, a magnetic shielding layer is formed on the surface of the passive member, and the magnetostrictive layer is formed thereon so as to lessen the adverse effects of the passive member caused by the magnetic characteristics of the passive member in strain measurement, that is, to reduce measurement errors. Alternatively, a magnetostrictive layer is formed on the surface of the passive member, or a magnetic shielding layer is partially forrmed on the surface of the passive member of soft magnetic material with high permeability, so as to lessen the influence of the passive member caused by thermal stresses of the passive member in strain measurement, that is, to reduce measurement errors. Further, there is provided a strain measuring device which facilitates formation of the magnetostrictive layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.