Moisture and density detector (MDD)
AssigneeMississippi State University
InventorsPhilip H. Steele, Jerome E. Cooper
Life of this patent
Estimating the term…
Abstract
A Moisture and Density Detector (MDD) that provides a method and apparatus to determine the moisture content and/or density of any dielectric material for various purposes. This device is very useful in detecting the moisture content (MC) of wood and wood-based materials, such as that of lumber in a dry kiln prior to, during and/or following drying. The MDD passes a radio frequency signal between opposed or adjacent capacitance electrodes and measures the signal strength and phase shift of the signal. The addition of phase shift and multiple frequencies improves the accuracy of the results.
Claims15
An apparatus for estimating at least one of moisture content and density of a dielectric material, comprising:
- a generator for generating a radio frequency signal in the range above DC and up to and including 1000 MHz;
- at least one pair of electrodes for transmitting and receiving said radio frequency signal through said dielectric material;
- a meter for measuring signal strength and phase shift of said radio frequency signal caused by interaction of said dielectric material;
- and
- a micro-processor for developing predetermined values of said signal strength and phase shift for said dielectric material, comprising;
- a meter for measuring signal strength and phase shift of a radio frequency signal caused by interaction of said radio frequency signal with said dielectric material using a known moisture content;
- a micro-processor for using a regression equation to determine an unknown moisture content for said dielectric material;
- and
- a micro-processor for using a regression equation to determine density for said dielectric material;
- a micro-processor for comparing said measured signal strength and phase shift of said radio frequency signal to said predetermined values to determine at least one of moisture content and density values.
A method for estimating at least one of moisture content and density of a dielectric material, comprising;
- generating a radio frequency signal in the range above DC and up to and including 1000 MHz;
- applying said radio frequency signal to at least one pair of electrodes for transmitting and receiving said radio frequency signal through said dielectric material;
- measuring signal strength and phase shift of said radio frequency signal caused by interaction of said dielectric material;
- developing predetermined values of said signal strength and phase shift for said dielectric material, comprising:
- measuring signal strength and phase shift of a radio frequency signal caused by interaction of said radio frequency signal with said dielectric material using a known moisture content;
- using a regression equation to determine an unknown moisture content for said dielectric material;
- and
- using a regression equation to determine density for said dielectric material;
- and
- comparing said measured signal strength and phase shift of said radio frequency signal to said predetermined values to determine at least one of moisture content and density values.
Dependencies are inferred from the claim text.