Air-coupled ultrasonic evaluation of coated textiles

The feasibility of on-line monitoring variations in the weight of a coating applied on a textile carrier by means of air-coupled ultrasound is demonstrated experimentally. To that purpose, coating layers of weight varying between 25 and 95 g/m/sup 2/ were applied on cotton carriers of different weight and the acoustic attenuation of transmitted ultrasound of 0.7 MHz was measured.