The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 15, 1987
Filed:
Nov. 02, 1981
Marvin H Weintraub, West Bloomfield, MI (US);
Donald R Bernier, Lake Orion, MI (US);
Larry Cameron, Sterling Heights, MI (US);
Water Sentry, Inc., Southfield, MI (US);
Abstract
An automatic control apparatus and method for sprinkling water over a predetermined area includes a control apparatus having first and second sensors disposed underground within the predetermined area, with the first sensor being disposed in a horizontal orientation immediately below the plant root level and the second sensor being disposed in a horizontal position a predetermined distance below the first sensor. The predetermined distance between the first and second sensors is selected to provide a measurement of the wilt-point moisture content of the type of soil found within the predetermined area. The first and second sensors are provided to measure the impedance of the soil therebetween, with the impedance being proportional to the moisture content of the soil. The output of the first and second sensors is compared with a predetermined electrical reference value established for the wilt-point moisture content of the type of soil found within the predetermined area. When the moisture content detected by the sensors is below the wilt-point, a comparator energizes a water control valve connected to a source of water to disperse water over the area until the desired wilt-point moisture content is achieved. In an alternate embodiment, the control apparatus is adapted for use in a multi-zone sprinkler system and includes a timer providing first and second predetermined time periods. During the first time period, the sensors are operative to control the application of water to the predetermined area; while during the second time period, the outputs of the sensors are inhibited to enable the water control valve to index to the next zone.