Pavement material microwave moisture-density measurement methods and apparatuses

A portable microwave material gauge for determining the quality of a pavement material comprising:

• an electromagnetic field generator configured to generate an electric field mode that penetrates into the material wherein the material includes a heterogeneous material including at least one of a pavement material and a soil material;
• a calibration data set represented by a relationship stored in memory of the portable microwave gauge;
• a sensor that supports the electric field mode and determines the response of the pavement material to the electric field wherein determining the response includes determining a change in the permittivity as a function of a change in the quality of the material;
• and
• an analyzer configured to correlate the sensor permittivity response to the calibration data set wherein correlating the response includes using stored relationships between the material quality and the sensor response using calibration samples having changes in permittivity as a function of quality.

A method for determining the quality of a pavement material comprising a portable microwave gauge including:

• generating an electromagnetic field producing at least one electric field mode that penetrates into the material wherein the material includes a heterogeneous mix including at least one of a pavement material, an aggregate material, and a soil material;
• incorporating a calibration data set represented by an equation or table stored in memory of the portable microwave gauge;
• measuring using a sensor of size and shape to support the electric field mode and to determine the response of the pavement material to the electric field, wherein determining the response includes determining a change in the permittivity as a function of a change in the quality of the material;
• and
• correlating the sensor permittivity response to the calibration data set or relation wherein correlating the response includes using stored relationships between the material quality and the sensor response using calibration samples having changes in permittivity as a function of quality.

A system comprising:

• a portable electromagnetic material sensor for determining the quality of a pavement material and a pavement material wherein a measurement of the sensor and system produces a impedance response based on permittivity of the material;
• an independent calibration data set or relationship between the measured permittivity response of the portable sensor and density of the pavement material;
• and
• an analyzer configured to correlate the portable electromagnetic sensor and material response to the density of the pavement material.