A method and apparatus for discriminating a valid return pulse from noise in a return signal received by an ultrasonic transducer in response to an interrogating pulse transmitted into a wall of a gas pipe by an ultrasonic transducer of a scan assembly. A discriminator is provided to compare the return...http://www.google.fr/patents/US5648613?utm_source=gb-gplus-shareBrevet US5648613 - Scan assembly and method for signal discrimination
Scan assembly and method for signal discrimination
