Monoaxially oriented piezoelectric polymer transducer for measurement of mechanical values on bodies
First Claim
1. A transducer for measuring mechanical values of hollow bodies, especially the pressure distribution within pipes, said transducer including a piezoelectric sensor element in the form of a flexible monoaxially-oriented polyvinylidene-fluoride polymer film having opposite top and bottom surfaces;
- separate electrically leading contact surfaces in the form of thin metallic layers connected to each of said top and bottom surfaces of said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film; and
means positioned to encompass one of said top and bottom contact surfaces so as to locate said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film adjacent the hollow body to be measured and to stretch said monoaxially-oriented polyvinylidene-fluoride polymer film such that it is under initial tension, the direction of initial tension X'"'"' and the direction X of the maximum piezoelectric stretch sensitivity of the film enclosing an angle of less than 45 degrees, the other of said contact surfaces being positioned between said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film and the hollow body from which measurements are to be taken.
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Abstract
A transducer comprising a piezoelectric measuring sensor element for measurement of mechanical values on hollow bodies, especially of the pressure distribution within pipes, the piezoelectric sensor element being a flexible piezoelectric film, the opposite surfaces of the film being in connection with electrically leading contact surfaces, and the measuring sensor element being at least partially and at least indirectly closely joinable to the surface of the hollow body.
87 Citations
9 Claims
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1. A transducer for measuring mechanical values of hollow bodies, especially the pressure distribution within pipes, said transducer including a piezoelectric sensor element in the form of a flexible monoaxially-oriented polyvinylidene-fluoride polymer film having opposite top and bottom surfaces;
- separate electrically leading contact surfaces in the form of thin metallic layers connected to each of said top and bottom surfaces of said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film; and
means positioned to encompass one of said top and bottom contact surfaces so as to locate said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film adjacent the hollow body to be measured and to stretch said monoaxially-oriented polyvinylidene-fluoride polymer film such that it is under initial tension, the direction of initial tension X'"'"' and the direction X of the maximum piezoelectric stretch sensitivity of the film enclosing an angle of less than 45 degrees, the other of said contact surfaces being positioned between said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film and the hollow body from which measurements are to be taken.
- separate electrically leading contact surfaces in the form of thin metallic layers connected to each of said top and bottom surfaces of said flexible piezoelectric monoaxially-oriented polyvinylidene-fluoride polymer film; and
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2. A transducer device for measuring the pressure distribution within pipes which includes a piezoelectric sensor element in the form of a flexible film having opposite top and bottom surfaces;
- separate electrically leading contact surfaces in the form of thin metallic layers connected to each of said top and bottom surfaces of said flexible piezoelectric film; and
an outer electrically-insulating foil positioned to encompass one of said top and bottom contact surfaces so as to wrap said flexible piezoelectric film around the pipe, said foil including means at the ends thereof for clamping together so as to stretch said foil around the circumference of the pipe. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
- separate electrically leading contact surfaces in the form of thin metallic layers connected to each of said top and bottom surfaces of said flexible piezoelectric film; and
Specification