An acoustic wave sensor utilizes one or more acoustic waves trapped in an acoustic wave cavity to detect the presence of one or more substances on a surface of the acoustic wave cavity. To detect the presence of ice, a trapped torsional acoustic wave is used. To detect water, an acoustic wave with flexural or compressional components is used. The sensor includes a number of transducers adjacent the acoustic wave cavity where a controller drives different sets of the transducers to generate different acoustic waves.
A device for mounting a sensor on a device being subjected to torque such as a shaft or plate in the form of a retaining ring having an opening or chamber sized to hold the sensor. The ring has a first open end for insertion of the sensor into the chamber or opening and a second end having a lip for retaining the sensor in the opening. The second end has an opening for the sensor wires or other connecting elements. The ring has threads on the outer periphery of the retaining ring for engaging similar threads on the device being subjected to torque.
A method for ultrasonically inspecting a generator field tooth for the detection, characterization and/or sizing of cracks thereat is disclosed. A monolithic piezoelectric transducer (MPT) productive of a test signal having a defined angle of refraction with respect to the tooth material is selected. The MPT is positioned at an outer surface of the tooth and oriented so as to direct the test signal to propagate through the tooth toward a load surface of the tooth where a butt joint of a set of wedges is disposed. The MPT is activated so as to test the load surface proximate the butt joint for cracks thereat.
A method for ultrasonically inspecting a generator field tooth for the detection, characterization and/or sizing of cracks thereat is disclosed. An electromagnetic acoustic transducer (EMAT) productive of a test signal having a defined angle of refraction with respect to the tooth material is selected. The EMAT is positioned at an outer surface of the tooth absent a fluid couplant and oriented so as to direct the test signal to propagate through the tooth toward a load surface of the tooth where a butt joint of a set of wedges is disposed. The EMAT is activated so as to test the load surface proximate the butt joint for cracks thereat.
A guide pipe is formed from a metal material, and its internal cross section has a circular shape whose diametric dimension gradually becomes smaller with a distance from an ultrasonic sensor. That is, the guide pipe is formed so that a route for transmitting an ultrasonic wave generated from the ultrasonic sensor may be tapered from this ultrasonic sensor toward a reflector plate. Thus, the acoustic pressure level of the ultrasonic wave which enters the reflector plate can be made higher than a value in a prior-art liquid level detecting apparatus. Accordingly, the energy of the ultrasonic wave generated from the ultrasonic sensor can be utilized for liquid level detection at a high efficiency, so that a fuel liquid level detecting apparatus capable of accurate liquid level detection can be provided.
An individual acoustic wave switch includes a body with a top section having an acoustic wave cavity formed therein and a base section extending downwardly from the top section. An acoustic wave transducer is mounted adjacent to a surface of the acoustic wave cavity opposite the touch surface thereof so as to generate an acoustic wave in the acoustic wave cavity and to pick up a signal representing the acoustic wave energy in the cavity. The acoustic wave switch is readily mounted in an aperture of a substrate through which the base of the switch extends.
