Method and apparatus for measuring dry density and water content of soil

A method for measuring dry density of soil, comprising the steps of:

• providing a plurality of spikes adapted to be driven into the soil;
• driving said plurality of spikes into the soil in spaced relationship;
• applying to said plurality of spikes an electrical signal suitable for time domain reflectometry;
• analyzing a reflected signal using time domain reflectometry to determine an apparent dielectric constant Ka of the soil and bulk electrical conductivity ECb of the soil;
• and
• calculating dry density ρd of the soil using a predetermined relationship between Ka, ECb and ρd.

A method for measuring gravimetric water content of soil, comprising the steps of:

• providing a plurality of spikes adapted to be driven into the soil;
• driving said plurality of spikes into the soil in spaced relationship;
• applying to said plurality of spikes an electrical signal suitable for time domain reflectometry;
• analyzing a reflected signal using time domain reflectometry to determine an apparent dielectric constant Ka of the soil and bulk electrical conductivity ECb of the soil;
• and
• calculating gravimetric water content w of the soil using a predetermined relationship between Ka, ECb, and w.

An apparatus for measuring dry density of soil, comprising:

• a plurality of spikes adapted to be driven into the soil in spaced relationship;
• means for applying to said plurality of spikes an electrical signal suitable for time domain reflectometry;
• means for analyzing a reflected signal using time domain reflectometry to determine an apparent dielectric constant Ka of the soil and bulk electrical conductivity ECb of the soil;
• and
• means for calculating dry density ρd of the soil using a predetermined relationship between Ka, ECb and ρd.

An apparatus for measuring gravimetric water content of soil, comprising:

• a plurality of spikes adapted to be driven into the soil in spaced relationship;
• means for applying to said plurality of spikes an electrical signal suitable for time domain reflectometry;
• means for analyzing a reflected signal using time domain reflectometry to determine an apparent dielectric constant Ka of the soil and bulk electrical conductivity ECb of the soil;
• and
• means for calculating gravimetric water content w of the soil using a predetermined relationship between Ka, ECb, and w.