Instrument for sensing level of granular materials
US3950653A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1975 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Jan 24, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/265
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A cylindrical housing contains both a circuit board and a pair of capacitive sensing electrodes. The pair of electrodes are adjacent the inside wall near an end that is to be wholly or partly covered with granular material in a container. Since an electric field is relatively concentrated about the electrodes, compared with the divergent field about the type having a single protruding electrode and depending on external ground planes, the circuits of the instrument show presence of material repeatedly quite close to a predetermined level. The unitary construction affords protection and permits the capacitive sensing electrodes to be mounted on the circuit board over a printed circuit tab.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.