Patent ID: 6684701
Filing Date: 2004-02-03
Classification: G01N

Abstract:
A method for ultrasonically measuring the porosity in a sample composite material by accessing only one side of the sample composite material, comprising the steps of:measuring a sample ultrasonic signal from the sample composite material; normalizing said sample ultrasonic signal; isolating a sample back-wall echo signal from said sample ultrasonic signal; determining a sample frequency spectrum of said sample back-wall ultrasonic signal; measuring a reference ultrasonic signal from a reference composite material; normalizing said reference ultrasonic signal; isolating a reference back-wall echo signal from said sample ultrasonic signal; determining a reference frequency spectrum of said reference back-wall ultrasonic signal; deriving the ultrasonic attenuation of said sample ultrasonic signal as the ratio of said sample frequency spectrum to said reference frequency spectrum over a predetermined frequency range; and comparing said derived ultrasonic attenuation to predetermined attenuation standards for evaluating the porosity of the sampled composite material.