Position transducer with temperature dependency compensation having a coil and displaceable core made of conductive and ferromagnetic materials
US5003258A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1988 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Sep 23, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2013
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The transducer comprises only a simple coil in which a core normally connected to a device the position of which is to be measured is displaced axially. The core comprises a rod of ferromagnetic material surrounded by a tube of good electrical conductivity but of small magnetic permeability. The coil is supplied by an alternating current producing eddy currents in the tube. The drop of sensitivity due to the increase of the resistivity of the tube with the increase of the temperature is compensated by the increase of the sensitivity due to the increase of the permeability of the rod with the increase of the temperature. The transducer is of light weight and of small dimensions and it is compensated in temperature in the temperature range comprised between -40.degree. C. and +20.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.