Moisture sensing system for an irrigation system
US4952868A · kind A · utility
49Cited by
46References
13Claims
0Family size
Inventor
Key dates
| Filing date | Oct 17, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Oct 17, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/189
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A moisture sensing device for an irrigation system. A pair of concentrically disposed cylindrical conductors are separated by a layer of beads, such that a capacitor is formed whose resistance will vary in response to the level of moisture present in the fibrous material. An electrical circuit is connected across the cylindrical conductors for measuring the variable resistance caused by the level of moisture present in the layer of beads. If the soil is dry enough to require watering, the sensor circuit will produce an output signal to the appropriate solenoid in the irrigation system to permit watering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.