Radio frequency linear position sensor using two subsequent harmonics
US5241278A · kind A · utility
23Cited by
7References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1992 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Jun 29, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D21/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus is adapted to detect the linear extension of a hydraulic cylinder. The hydraulic cylinder defines a variable length coaxial resonant cavity. Under the control of a controller, a transmitting section and a receiving section are used to determine the linear extension of the hydraulic cylinder. The controller detects two subsequent harmonics of the resonant frequency and responsively determines the resonant frequency. The linear extension is determined as a function of the resonant frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.