Patent ID: 7170302

Claim:
A capacitive soil moisture sensor having a lower portion adapted to be inserted into the earth comprising of: a sensor carrier comprising; a body having a generally spade shaped with one tapered end, one opposite flat end and two parallel sides, said body being of a thin structurally rigid material with a plurality of narrow ribs parallel to said two parallel sides, a header enclosure having a generally rectangular box shaped with one top face, one opposite bottom face, said header being joined at said bottom face to said body at said flat end such that said header's said bottom face is perpendicular to said body and such that said bottom face over-hangs said body generally equal distance on all sides, a first electrode comprising a plurality of sheets of conductive material, a second electrode comprising a plurality of sheets of conductive material, a protective layer comprising of a plurality of corrosion resistant and abrasive resistant material, said first electrode being joined onto the surface of one face of said sensor carrier's said body, said second electrode being joined onto the surface of said face of said sensor carrier's said body in the same orientation and alignment as said first electrode, said first electrode and said second electrode positioned so they do not touch, said protective layer joined onto the surface of said face of said sensor carrier's said body over said first electrode and said second electrode, said first electrode and said second electrode so positioned on said sensor carrier to be inserted into the earth so forms a planar capacitor with soil as dielectric.