SENSING OF MOISTURE CONTENT IN SOIL

• US 3,803,570 A
• Filed: 02/15/1972
• Issued: 04/09/1974
• Est. Priority Date: 02/15/1972
• Status: Expired due to Term

• Current Assignee: Eric C. Campbell, Reed G. Crockett, Wayne K. Barlow
• Original Assignee: Eric C. Campbell, Reed G. Crockett, Wayne K. Barlow
• Inventors: Barlow, Wayne K., Campbell, Eric C., Crockett, Reed G.
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/226,587
• Time in Patent Office: 784 Days
• Field of Search: 340/373,235 73/34R,34C 324/65P,65R
• US Class Current: 318/643
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825

Abstract

A moisture sensing apparatus and method, the apparatus comprising a capacitive moisture sensing probe insertable into the earth at a desired location and establishing an electrical signal indicative of the moisture content of the earth at said desired location, a servomechanism energized by said signal, and a semaphore positionable by said servomechanism to provide a visual indication of the moisture content of said soil. A system is also disclosed for permitting the moisture sensing device to control distribution of water to the soil in response to said signals.

Claims

1. A soil moisture field measuring apparatus comprising:

earth insertable probe means, support means, circuit means coupled to said probe means for monitoring the instantaneous magnitude of an electrical characteristic of the moisture content of said earth said circuit means having a variable electrical output signal proportional to the instantaneous value of percentage soil moisture within the range between zero and saturation, signaling means; and

servo means responsive to said output signal to position said signaling means in a range of indications corresponding to said soil moisture, said servo means and said signaling means being supported above ground by said support means.

2. The device of claim 1 wherein said signaling means comprises:

semaphore means.

3. The device of claim 2 wherein said semaphore means comprises:

an arm pivotally carried on said support means and radially positionable by said servo means, flag means carried by said arm.

4. The device of claim 3 wherein:

said arm is centrally pivotally carried up on the support means, said flag means comprise dissimilar visual indicators mounted to the arm on opposite sides of the central pivot site.

5. The device of claim 1 wherein said circuit means are electrically connected to and energized by a battery.

6. The device of claim 1 wherein said apparatus comprises:

an elongated shaft, comprising said probe means, formed of electrically conductive material and having a tip portion formed to facilitate insertion into the earth, and a protective sleeve disposed about said shaft and extending along the entire length of said shaft except for said tip portion.

7. A soil moisture system comprising a plurality of soil moisture monitoring units for distribution through a substantial area of land, each unit comprising:

earth insertable probe means, support means, circuit means coupled to said probe means serving for monitoring the instantaneous magnitude of an electrical characteristic of the moisture content of said earth said circuit means having a variable electrical output signal proportional to the instantaneous value of percentage soil moisture within the range between zero and saturation, signaling means; and

servo means responsive to said output signal to position said signaling means in a range of indications corresponding to said soil moisture, said servo means and said signaling means being supported above ground by said support means.

8. A portable and self-contained field soil moisture detecting apparatus comprising:

a portable source of electrical energy, probe means for insertion into the soil comprising electronic means sensing an electrical characteristic of the soil which is proportional to said soil moisture, electronic means creating an electrical signal representative of the sensed characteristic and electrical cable means connecting the probe means to the source, a ground-engaging mast projecting a substantial distance into the air and on which the electrical energy source is carried, long distance visual signaling means the angular oriEntation of which is an accurate representation of soil moisture at the probe means carried in an elevated position above the ground by the mast, a servo means mounted in an elevated location upon the mast and having means connected to and controlling the orientation of the signaling means, and means communicating to the control input means of the servo means the electrical signal representative of the soil moisture condition sensed by the probe means causing angular reorientation of the signaling means when the prior angular orientation is not accurately indicative of the present soil moisture condition.