Abstract
This paper describes a technique for measuring the thickness of coating on the double-sided coating steel plates by means of acoustic resonant spectroscopy. The both sides of the samples were covered with coatings of epoxy resin, and the thickness of the coatings was from 10 to 40pm. The acoustic resonance related with the top and bottom coatings of all samples were observed by the 100MHz focused ultrasonic transducer, and the thickness of coatings on both side of the plates were successfully evaluated from their resonant frequencies.
