Capacitive acoustic wave detector and method of using same
First Claim
1. A capacitive detector for detecting acoustic waves propagated through a non-gaseous material, comprising:
- a dielectric having first and second substantially parallel faces, the first face being acoustically isolated from a surface of the material; and
an electrode electrically coupled to the second face of said dielectric;
said electrode and material surface being adapted to connect to an inductance capacitance circuit for measuring an oscillating capacitance between said electrode and the material surface as the material surface is oscillated by each acoustic wave propagated through the material, the changing capacitance being indicative of acoustic waves propagated through the material.
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Accused Products
Abstract
A capacitor having two substantially parallel conductive faces is acoustically coupled to a conductive sample end such that the sample face is one end of the capacitor. A non-contacting dielectric may serve as a spacer between the two conductive plates. The formed capacitor is connected to an LC oscillator circuit such as a Hartley oscillator circuit producing an output frequency which is a function of the capacitor spacing. This capacitance oscillates as the sample end coating is oscillated by an acoustic wave generated in the sample by a transmitting transducer. The electrical output can serve as an absolute indicator of acoustic wave displacement.
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Citations
16 Claims
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1. A capacitive detector for detecting acoustic waves propagated through a non-gaseous material, comprising:
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a dielectric having first and second substantially parallel faces, the first face being acoustically isolated from a surface of the material; and an electrode electrically coupled to the second face of said dielectric; said electrode and material surface being adapted to connect to an inductance capacitance circuit for measuring an oscillating capacitance between said electrode and the material surface as the material surface is oscillated by each acoustic wave propagated through the material, the changing capacitance being indicative of acoustic waves propagated through the material. - View Dependent Claims (2, 3)
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4. A system for detecting acoustic waves propagated through a material, comprising:
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a dielectric having first and second substantially parallel faces, the first face adapted to be acoustically isolated from a surface of the material; an electrode electrically coupled to the second face of said dielectric; and an inductance-capacitance circuit outputting a frequency based on an oscillating capacitance between said electrode and the material surface as the material surface is oscillated by the acoustic waves propagated through the material, the output frequency being indicative of the propagated acoustic waves. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of detecting acoustic waves propagating in a material, comprising the steps of:
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applying a dielectric having first and second substantially parallel faces to a material surface such that the first face of the dielectric is acoustically isolated from the material surface; applying an electrode in contact with the second dielectric face; measuring a change in capacitance between the electrode and the material surface as the material surface oscillates due to the propagated acoustic waves, the measured capacitance change being indicative of the propagated acoustic waves. - View Dependent Claims (14, 15, 16)
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Specification