Eddy current distance signal apparatus with temperature change compensation means
US4716366A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1985 |
| Grant date | Dec 29, 1987 |
| Priority date | — |
| Expiry date | Jun 27, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/023
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Eddy current distance measuring apparatus includes a multiplier connected to one secondary coil of a pair of secondary coils in an eddy current sensor. The secondary coil outputs are inputted to a differential amplifier, and the resulting difference is adjusted to be zero when an object the distance to which is to be measured is not present. Thereafter, the sensor is located within measuring distance of, e.g., a steel plate, and the output of the differential amplifier is combined by an amplifier circuit with an oscillator output supplying a current to the primary coil of the sensor. An eddy current distance signal output is thus obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.