Dielectric sensor apparatus
AssigneeMetriguard Inc.
InventorsFriend K. Bechtel, James R. Allen, Daniel A. Uskoski
Life of this patent
Estimating the term…
Abstract
Method and apparatus are described for obtaining information about the real and imaginary parts of permittivity in dielectric materials and relating this information to other properties of the materials.
Claims12
An apparatus for obtaining a measure of the amount of anisotropy of an electrical property in an adjacent dielectric material specimen about a selected test point in a surface of the specimen, the electrical property being considered over directions in a measurement plane substantially parallel to the specimen surface at the test point, the apparatus comprising:
- first and second electrode means having a common axis substantially perpendicular to the measurement plane at the test point;
- the first electrode means having at least one electrode symmetrically arranged about the axis;
- the second electrode means comprising a plurality of electrodes angularly arranged about the axis for applying a time varying electric field in at least two directions in a neighborhood of the test point;
- the electrodes of the second electrode means being spaced apart from one another and from the electrodes of the first electrode means;
- signal generating means for applying a drive set of time-varying electric potential signals to the electrodes of the second electrode means;
- signal detecting means for obtaining from the first electrode means during a first measurement time interval a first signal proportional to the cosine of twice the angle in the measurement plane from the reference direction to the direction of electrical property maximum and during a second measurement time interval a second signal proportional to the sine of twice the angle in the measurement plane from the reference direction to the direction of electrical property maximum;
- transport means for applying the apparatus at a plurality of test points in the surface of the dielectric material specimen;
- processing means for processing, at each of the plurality of test points, the first and second signals to obtain the angle in the measurement plane from a reference direction to the direction of electrical property maximum;
- and
- computing means for computing a measure of the amount of anisotropy of the dielectric material specimen as a function of the angles at the plurality of test points.
An apparatus for obtaining a measure of the amount of anisotropy of an electrical property in an adjacent dielectric material specimen about a selected test point in a surface of the specimen, the electrical property being considered over directions in a measurement plane substantially parallel to the specimen surface at the test point, the apparatus comprising:
- first and second electrode means having a common axis substantially perpendicular to the measurement plane at the test point;
- the first electrode means having at least one electrode symmetrically arranged about the axis;
- the second electrode means comprising a plurality of electrodes angularly arranged about the axis for applying a time varying electric field in at least two directions in a neighborhood of the test point;
- the electrodes of the second electrode means being spaced apart from one another and from the electrodes of the first electrode means;
- signal generating means for applying a drive set of time-varying electric potential signals to the electrodes of the second electrode means;
- signal detecting means for obtaining from the first electrode means during a first measurement time interval a first signal proportional to the cosine of twice the angle in the measurement plane from the reference direction to the direction of electrical property maximum, during a second measurement time interval a second signal proportional to the sine of twice the angle in the measurement plane from the reference direction to the direction of electrical property maximum and during a third measurement time interval a third signal proportional to the isotropic component of the electrical property near the test point in directions of the measurement plane;
- and
- signal processing means for processing the first and second signals to obtain the measure of the amount of anisotropy;
- and the third signal to obtain a measure of the isotropic component of the electrical property near the test point in directions of the measurement plane.
A measurement system for obtaining a measure of the amount of alignment of a dielectric material specimen, the system comprising:
- signal detecting means for determining at each of a plurality of test points in a surface of the specimen, a first value equal to the cosine of twice the angle of the direction of an electrical property maximum and a second value equal to the sine of twice the angle of the direction of the electrical property maximum, the electrical property being considered over directions in a measurement plane substantially parallel to the specimen surface at the test point, the directions at the plurality of test points all being relative to a common reference direction;
- and
- signal processing means for determining the amount of alignment as a function of the square root of the sum of the squared average of the first values and the squared average of the second values.
A measurement system for obtaining a measure of the general direction of alignment of the dielectric specimen, the system comprising:
- signal detecting means for determining at each of a plurality of test points in a surface of the specimen, a first value equal to the cosine of twice the angle of the direction of an electrical property maximum and a second value equal to the sine of twice the angle of the direction of the electrical property maximum, the electrical property being considered over directions in a measurement plane substantially parallel to the specimen surface at the test point, the directions at the plurality of test points all being relative to a common reference direction;
- and
- signal processing means for obtaining from the first and second values at the plurality of test points the general direction of alignment as a function of the quotient of the average of the second values divided by the average of the first values.
A measurement system for obtaining a parameter describing the average size of constituent particles in a dielectric material specimen, the system comprising:
- signal detecting means for determining at each of a plurality of test points in a surface of the specimen, a first value equal to the cosine of twice the angle of the direction of an electrical property maximum and a second value equal to the sine of twice the angle of the direction of the electrical property maximum, the electrical property being considered over directions in a measurement plane substantially parallel to the specimen surface at the test point, the directions at the plurality of test points all being relative to a common reference, direction;
- and
- signal processing means for obtaining from the first and second values at the plurality of test points the parameter describing the average size of constituent particles in the dielectric material specimen.
Dependencies are inferred from the claim text.