Magnetomechanical transducer utilizing resonant frequency shifts to measure pressure in response to displacement of a pressure sensitive device
US4720676A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1983 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Dec 5, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0029
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A target adapted for use in a magnetomechanical transducer system is activated by an ac magnetic field and a variable dc bias field to produce a resonant frequency which corresponds to the effective strength of the dc bias field. The target includes an elongated ductile strip of magnetostrictive ferromagnetic material enclosed in a nonmagnetic container in a manner to allow the strip to vibrate freely. The strip has a magnetomechanical coupling factor, k greater than O, where K=zero.sqroot.(1-fr.sup.2 /fa.sup.2), fr and fa being the resonant and antiresonant frequencies, respectfully. The system is economical to construct and affords accurate and efficient measurement of pressure via displacements and angles of pressure sensitive devices at locations proximate to or remote from the signal source (target).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.