Abstract: A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies, each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element then pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic stack is primarily used in pulse-echo analysis of metal casing wall thickness and cement bond quality detection of wells.

Abstract: A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer or transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission or reflection of a transmitted ultrasonic signal, or which does not allow the reception or reflection of the transmitted ultrasonic signal, depending on the host configuration.

Abstract: A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer or transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission or reflection of a transmitted ultrasonic signal, or which does not allow the reception or reflection of the transmitted ultrasonic signal, depending on the host configuration.

Abstract: A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies, each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element then pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic stack is primarily used in pulse-echo analysis of metal casing wall thickness and cement bond quality detection of wells.

Abstract: Low frequency pulse-echo ultrasonic transducers are provided especially suited for use in downhole cement bond evaluation, but usable for various applications. One frequency pulse-echo ultrasonic transducer comprises a transducer stack having alternating layers of a piezoceramic element and an ultrasonic attenuating element that is preferably acoustic impedance matched to the piezoceramic elements in order to reduce the Q of the transducer stack. Another low frequency pulse-echo ultrasonic transducer comprises an assembly having the present transducer stack disposed on an acoustic attenuating backing and a front face. Yet another low frequency pulse-echo ultrasonic transducer comprises a transducer composite made from a lead metaniobate. Still another frequency pulse-echo ultrasonic transducer comprises a composite stack. A further low frequency pulse-echo ultrasonic transducer comprises a composite stack, wherein multiple drive elements allow driving individual elements at different times.

Abstract: A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission of a transmitted ultrasonic signal, or which does not allow the reception of the transmitted ultrasonic signal, depending on the host configuration.

Abstract: A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies; each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element the pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic elements are bonded together and onto a critically damped backing of tungsten.

Abstract: An insulated sounder assembly may include: a) a sounder cup having a bottom and a sidewall; b) a piezoelectric element positioned in the bottom of the cup; c) a potting layer within the sounder cup and spaced apart from the piezoelectric element so that the potting layer contacts the cup sidewall for a distance of at least 3 mm around the entire circumference of the cup, and so that a gap exists between the piezoelectric element and the potting layer, with the gap being sufficient to allow vibration of the piezoelectric element in the sounder cup without restriction by the potting layer; and d) an electrical contact wire attached to the piezoelectric element to provide a voltage to the piezoelectric element, wherein the electrical contact wire passes through the potting layer so that at least 3 mm of bare wire is completely embedded in said potting layer.

Abstract: A piezoceramic pulse-echo acoustic transducer includes protection layers for the piezoceramic that are tuned to the piezoceramic so as to optimize pulse-echo signal response (i.e. greater output signal bandwidth and increased return signal sensitivity). The protection layers are tuned to the piezoceramic via material selection and thickness. The acoustic transducer has a backing, a piezoceramic adjacent the backing, an intermediate protection layer adjacent the piezoceramic, and a front protection layer adjacent the intermediate protection layer and opposite the piezoceramic. The front and intermediate protection layers are tuned to the piezoceramic via their acoustic impedance such that the acoustic impedance of the intermediate layer is greater than the acoustic impedance of the piezoceramic and of the front protection layer. The acoustic impedance of the front protection layer is less than the acoustic impedance of the piezoceramic.

Abstract: A device for acoustic measuring in a medium in a borehole such as velocity of sound in the medium or velocity of the medium, includes at least a first acoustic array situated in a first, slanted sidewall of a measuring area and operating to emit a series of acoustic waveforms across a measuring area. In one form, the device includes a second acoustic array situated in a second, slanted sidewall of the measuring area and operating to receive an acoustic signal resulting from the emitted series of acoustic waveforms or to receive said acoustic signal and emit a second series of acoustic waveforms.

Abstract: A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fHt at a temperature T defined by fHt=(vt/2?)(?(A/voL)) were vt is the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vo is the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of ?(A/voL) at a rate and in a manner that balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2?)(?(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range, thereby holding the value of fH substantially constant across the temperature range.

Abstract: A pressure-compensated transducer assembly has an inner housing with a closed transducer end and an outer housing with an open transducer end. A piezoelectric assembly is in the closed transducer end of the inner housing. A liquid-filled inter-housing space is between the outer housing and the inner housing, and has a transducer end open to the environment and a connection end open to the piezo assembly space. A blocking member separates the transducer end of the inter-housing space from the connection end, and prevents fluids from flowing between the two ends. The blocking member is movable within the inter-housing space in response to pressure differences the environment and the interior space.

Abstract: An insulated sounder assembly may include: a) a sounder cup having a bottom and a sidewall; b) a piezoelectric element positioned in the bottom of the cup; c) a potting layer within the sounder cup and spaced apart from the piezoelectric element so that the potting layer contacts the cup sidewall for a distance of at least 3 mm around the entire circumference of the cup, and so that a gap exists between the piezoelectric element and the potting layer, with the gap being sufficient to allow vibration of the piezoelectric element in the sounder cup without restriction by the potting layer; and d) an electrical contact wire attached to the piezoelectric element to provide a voltage to the piezoelectric element, wherein the electrical contact wire passes through the potting layer so that at least 3 mm of bare wire is completely embedded in said potting layer.

Abstract: A device for acoustic measuring in a medium in a borehole such as velocity of sound in the medium or velocity of the medium, includes at least a first acoustic array situated in a first, slanted sidewall of a measuring area and operating to emit a series of acoustic waveforms across a measuring area. In one form, the device includes a second acoustic array situated in a second, slanted sidewall of the measuring area and operating to receive an acoustic signal resulting from the emitted series of acoustic waveforms or to receive said acoustic signal and emit a second series of acoustic waveforms.

Abstract: A piezoceramic pulse-echo acoustic transducer includes protection layers for the piezoceramic that are tuned to the piezoceramic so as to optimize pulse-echo signal response (i.e. greater output signal bandwidth and increased return signal sensitivity). The protection layers are tuned to the piezoceramic via material selection and thickness. The acoustic transducer has a backing, a piezoceramic adjacent the backing, an intermediate protection layer adjacent the piezoceramic, and a front protection layer adjacent the intermediate protection layer and opposite the piezoceramic. The front and intermediate protection layers are tuned to the piezoceramic via their acoustic impedance such that the acoustic impedance of the intermediate layer is greater than the acoustic impedance of the piezoceramic and of the front protection layer. The acoustic impedance of the front protection layer is less than the acoustic impedance of the piezoceramic.

Abstract: Low frequency pulse-echo ultrasonic transducers are provided especially suited for use in downhole cement bond evaluation, but usable for various applications. One frequency pulse-echo ultrasonic transducer comprises a transducer stack having alternating layers of a piezoceramic element and an ultrasonic attenuating element that is preferably acoustic impedance matched to the piezoceramic elements in order to reduce the Q of the transducer stack. Another low frequency pulse-echo ultrasonic transducer comprises an assembly having the present transducer stack disposed on an acoustic attenuating backing and a front face. Yet another low frequency pulse-echo ultrasonic transducer comprises a transducer composite made from a lead metaniobate. Still another frequency pulse-echo ultrasonic transducer comprises a composite stack. A further low frequency pulse-echo ultrasonic transducer comprises a composite stack, wherein multiple drive elements allow driving individual elements at different times.

Abstract: A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission of a transmitted ultrasonic signal, or which does not allow the reception of the transmitted ultrasonic signal, depending on the host configuration.

Abstract: A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fHt at a temperature T defined by fHt=(vt/2?)(?(A/voL)) were vt is the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vo is the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of ?(A/voL) at a rate and in a manner that balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2?)(?(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range, thereby holding the value of fH substantially constant across the temperature range.

Abstract: A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies; each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element the pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic elements are bonded together and onto a critically damped backing of tungsten.

Abstract: A method for identifying a warhead in an aircraft launch tube includes providing a pattern of grooves on the surface of a warhead, with the pattern of grooves being associated with an identification code identifying the warhead or a characteristic of it, providing the warhead in an aircraft launch tube, providing a piezoelectric transducer on the launch tube, emitting an ultrasonic wave from the piezoelectric transducer to the pattern of grooves, where the wave encounters the pattern of grooves at an angle of less than 90° so that waves striking the interior of a groove are reflected back to the transducer as echo waves, while waves not striking the interior of a groove are reflected away from the transducer, and reading the pattern of returning echo waves to determine the identification code indicated by the pattern of grooves on the warhead.