Measurements of surface texture using ultrasound

A new ultrasonic spectroscopic technique has been developed to measure the gross surface texture of materials. A surface roughness coefficient has been introduced that specifies the texture of a surface on a quantitative basis. Comprehensive theoretical models based on analyzing the frequency spectrum of the received ultrasonic signals have been developed to study the effect of surface texture on reflected ultrasonic pulses from rough surfaces. A minimization function obtains the best match between theoretical models and actual measurements in such a way that the resultant coefficient for the best match represents the surface roughness.