Mechanically excited resonant-element sensor
US4470313A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1982 |
| Grant date | Sep 11, 1984 |
| Priority date | — |
| Expiry date | Apr 5, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S73/01
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A resonant wire instrument for producing a measurement signal, which is derived from the resonant frequency of a vibratable wire tensioned in accordance with the magnitude of a physical variable being measured, wherein a force impulse produced mechanically by an apparatus is applied to displace laterally one end of the vibratable wire so as to excite the wire into resonant motion. In one embodiment, the one end is rigidly attached to a housing and a piston applies a transverse force impulse to that end by momentarily striking the housing. In another embodiment, the one end is connected to a piezoelectric crystal which responds to a short-duration electric field to displace momentarily that end. In one species of this other embodiment, the crystal is made to oscillate at the resonant frequency of the tensioned wire by the application of an alternating-polarity voltage signal that is generated by a voltage source having an output connected to the crystal, and a feedback circuit coupled to receive the measurement signal operates to produce a control signal that is used for controlling the voltage source so that the voltage signal being applied to the crystal has a frequency which vari…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.