Piezoelectric ratio weighing device
US4623030A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1985 |
| Grant date | Nov 18, 1986 |
| Priority date | — |
| Expiry date | Oct 21, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2011/0006
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A piezoelectric device is used to determine a ratio of a second weight with an original weight where the second weight is less than the original weight. A piezoelectric driver is resiliently attached to a base that is isolated from vibrations. A piezoelectric receiver and a reed are resiliently attached to the piezoelectric driver so that (1) the read is moved in response to motion of the piezoelectric driver, and (2) the piezoelectric receiver gives an electric signal out proportional to motion of the system. The entire system is set to operate on the leading edge of the resonant frequency for the system. By applying an oscillating sine wave voltage, such as 140 hertz, to the piezoelectric driver, and by applying an unknown mass to the tip of the reed, a first output is obtained from the piezoelectric receiver which represents the original weight. Next by removing part of the mass by any convenient means, such as heat, a second output is obtained that represents the second weight. By a ratio of the second output/first output (or a signal equivalent to the weights being measured), the percent of the mass remaining is determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.