In situ papermachine web sound velocity test

摘要

An on-line instrument in rolling contact with a papermachine web determines the web's strength and elastic modulus properties by intermittently pulsed sonic waves transmitted through the traveling web mass between a full circle, piezoelectric transducer emitter and identical receiving transducers respectively displaced from the emitter along the MD and CD web axes. Transducer signals from the receivers are analyzed by cross-correlation function techniques relative to the original stimulation reference signal to isolate the desired data signal from integral noise.