Irrigation controller
US6314340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1998 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | Nov 2, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01G25/167
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An irrigation controller collects daily high and low temperature data. The controller then processes this collected temperature data in accordance with the Hargreaves equation to determine a reference evapotranspiration value. The controller further adjusts the reference evapotranspiration value to account for the type of vegetation at the site and a localized Hargreaves equation deviation factor to generate an adjusted evapotranspiration value which represents an estimation of the current watering needs for the specific plants at that specific site. The controller then divides the locally adjusted evapotranspiration value by a sprinkler head average precipitation rate to determine a run time for irrigation. Irrigation for the site is then initiated lasting for the duration of the determined run time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.