Brevetto US5445178 - Soil moisture sensor - Google Brevetti. The following detailed description is of the best presently contemplated mode of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. The present invention relates generally to moisture sensor devices, systems and methods of making and using the same. In preferred embodiments, a moisture sensor device has a pair of elongated probe-like sensor elements which are installed (inserted or otherwise disposed) in a medium to be monitored. In general, the sensor elements and the medium at and around the installation location provide a capacitance value dependent upon the dielectric constant of the medium at and around the installation location.
FIGS. 1 and 2 show a moisture sensor device 10 according to a preferred embodiment of the present invention. 1. 2. Brevetto US5424649 - Soil moisture sensor - Google Brevetti. Referring now to FIG. 1, there is shown a front view of a preferred embodiment of a soil moisture sensor 10 constructed and operated in accordance with the principles of the present invention.
Sensor 10 comprises a pair of cylindrically-shaped electrodes 12, 14 of a predetermined length, each being anchored in a sealing material 15 like epoxy at an upper end thereof in a housing 16, with its free end extending into soil (not shown) for moisture measurement purposes. Each electrode 12, 14 is coated with a thin layer of dielectric material 17 over its length, and the electrode pair is connected to a conversion circuit 18 for soil moisture measurement, as described further herein. A cable 19 enables external connection of the output signal of sensor 10. Rout=radius of the electrode with dielectric coating Rin=radius of the electrode alone The frequency of astable multivibrator 24 is controlled by the setting of variable resistor R1. A variation of these designs is given in U.S. In U.S. Nota di reindirizzamento. A cheap soil moisture sensor - GardenBot.
The Soil Moisture Sensor You are building a cheap soil moisture sensor so the brain can read the amount of moisture in the soil. The version we are building is very low tech, but it is also very cheap and easy to build. It consists of a block of packing foam with a couple of wires shoved into it. And the great thing is that it's possible to use reclaimed materials in much of it's construction. If you cruise around the web, you will find many other types of soil moisture sensor -- some home-made, some commercial. . * Check it out! Supplies: (see the parts page)galvanized steel wire -- 12 gage or equivalent packing foam block (e.g. inside a product box for home electronics) -- the slightly flexible kind is better (less brittle than styrofoam)soldering iron and solderlead wires The general idea is that we want two probes -- metal rods, kept about equal distance apart, that we can bury in the soil.
Notes: Here is a diagram for constructing the actual probe. Step-By-Step.