Method and apparatus for measuring distance
US3997835A · kind A · utility
24Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1974 |
| Grant date | Dec 14, 1976 |
| Priority date | — |
| Expiry date | Nov 7, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/202
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In measuring the distance between a measuring sensor and a metallic body, the sensor is comprised by a resonance circuit including a capacitor and a coil, and the sensor is connected to the input of a Q multiplier circuit which is impressed with an AC signal having a predetermined frequency. The non-linear distance-inductance characteristic of the coil is compensated for by adjusting the selectivity of the resonance circuit so that the amplifier included in the Q multiplier circuit produces a linear output. Such compensation is performed by adjusting the gain and/or the amount of positive feedback of the Q multiplier circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.