Patent ID: 7669458

Claim:
A method for determining the density of a material, comprising: moving a roller along a first section of material; applying with the roller a vibratory energy at a predetermined frequency and amplitude to the first section of the material as the roller moves therealong; measuring the vibratory characteristics of the roller on the first section of material; producing a first section vibration signal representing the vibratory characteristics of the roller on the first section of material; measuring the density of the first section of material; correlating the density of the first section of material and the first section vibration signal; moving the roller along a second section of material; applying with the roller a vibratory energy at a predetermined frequency and amplitude to the second section of material as the roller moves therealong; measuring the vibratory characteristics of the roller on the second section of material; producing a second section vibration signal representing the vibratory characteristics of the roller on the second section of material; and comparing the second section vibratory signal to the first section vibratory signal to estimate the density of the second section of material.