In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels
An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.
- Research Organization:
- Institute of Paper Chemistry
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-86CE40777
- Assignee:
- Inst. of Paper Science and Technology, Inc., Atlanta, GA (United States)
- Patent Number(s):
- US 5,719,337/A/
- Application Number:
- PAN: 8-760,839
- OSTI ID:
- 570412
- Resource Relation:
- Other Information: PBD: 17 Feb 1998
- Country of Publication:
- United States
- Language:
- English
Thickness Direction Measurements in Paper Materials Using Ultrasonic Sensors Immersed in Water-Filled Wheels
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book | January 1991 |
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