Method and apparatus for measuring the distance between a measuring transducer and an opposing surface, particularly with paper pulp equipment
US4810964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1986 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Jan 22, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring the spacing between a pair of surfaces, at least one of which is of electrically conductive and/or ferromagnetic material, so that the wear of one of the surfaces can be determined. A measuring transducer having a core with coils, and a reference transducer substantially identical to the measuring transducer, are the basic elements. The measuring transducer is mounted close to an opposing surface of conductive and/or ferromagnetic material with a gap between them, and the reference transducer is mounted with a constant gap spacing between it and a reference surface of the same material as the opposing surface. A current detector, and first and second sources of electrical current, are operatively connected to coils of the transducers so that by sensing the difference in ampere-turns of the coils of respective transducers, or the difference between the magnetic fields produced by coils of the respective transducers, or both, an indication of the distance between the measuring transducer and the opposing surface is provided. The measuring transducer (or a plurality of them) is preferably mounted within a body (such as ferromagnetic material body) …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.