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AssigneeInstitute of Paper Science and Technology, Inc.
InventorsMaclin S. Hall, Pierre H. Brodeur, Theodore G. Jackson
Estimating the term…
A system for relatively accurately measuring the velocity and time of flight of ultrasonic signals in the thickness direction through moving web-like materials, such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of the moving web-like material. The ultrasonic transducers are disposed in fluid-filled wheels to provide acoustical coupling between the transducers and the web-like material. In order to eliminate errors, known as trigger jitter, inherent in systems used to digitize ultrasonic signals for manipulation by a digital computer, a pulse echo box is provided to enable the capture of a reflected ultrasonic signal in addition to the ultrasonic signal transmitted through the web. By cross-correlating the transmitted and reflected ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.
A system for making ultrasonic measurements on a moving web defining opposing planar surfaces of a predetermined material having a predetermined thickness, the ultrasonic measurements being made in a direction generally perpendicular to said opposing planar surfaces of the moving web, the system comprising:
A system for making ultrasonic measurements on a moving web having opposing planar surfaces of a predetermined material comprising:
Dependencies are inferred from the claim text.