Device for the capacitive measurement of levels
US4467646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1981 |
| Grant date | Aug 28, 1984 |
| Priority date | — |
| Expiry date | Nov 6, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/263
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for the capacitive measurement of liquid levels, particularly in an automobile tank has a measurement sensor with measurement electrodes arranged concentric to each other forming a measurement capacitor, the space between the measurement electrodes communicating at a variable height with the liquid to be measured, and a channel within an inner of the measurement electrodes through which the liquid is drawn up. Compensation electrodes form a compensation capacitor in a suction path of the liquid with a constant level of the liquid by which the influence of different dielectric constants of the liquid on the result of a measurement is compensatable in an evaluation circuit to which the measurement capacitor and the compensation capacitor are connected. A sump vessel has a bottom disposed lower than an upper opening of the channel within the inner measurement electrode. The compensation electrodes are arranged in the sump vessel. An overflow is in liquid-conducting communication with the channel and the sump vessel, and a suction tube for the liquid extends substantially to the bottom of the sump vessel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.