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: Among other things, there are disclosed embodiments of a well-logging tool that inspects features of the down-hole environment using ultrasonic signals with a frequency in the range of 3-5 MHz. The ultrasonic signals are encoded, and their time-of-flight and amplitude provide information on features of interior surface of the casing on the order of 1 mm, and on the quality of the cement bond behind the casing.

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 PZT-type piezoelectric ceramic material having a perovskite structure of the ABO3 type. The stoichiometric ratio of AB is 1:1, with the “A” component being Pb1-zSrz and the “B” component being (Mn1/3Sb2/3)x(ZryTi1-y)1-x. Z is between 0.02 and 0.03, x is between 0.03 and 0.07, and y is between 0.40 and 0.60. The material further comprises dopants, with the dopants comprising Ce, Cu, and Nb dopants, with each of the Ce, Cu, and Nb dopants being provided in an amount of up to 2 wt. %, with the combined amount of the Ce, Cu, and Nb2 dopants being between 1 wt. % and 4 wt. %. Methods for preparing the PZT ceramic materials by combining oxides of Pb, Sr, Mn, Sb, Zr, Ti, Nb, Cu, and Ce and calcining the combined oxides so as to produce a PZT composition of the stated formula are also disclosed.

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: A class of ceramic compositions according to the formula Pb(1-z)Mz(Mn1/3Sb2/3)x(ZryTi1-y)1-xO3 where M is selected to be either Sr or Ba, x is selected to be between 0.01 and 0.1, y is selected to be between 0.35 and 0.55, and z is selected to be between 0.01 and 0.10. In some embodiments of the above composition, one or more dopants is added to the compositions. The dopant(s) may be selected from the group comprising: PbO, CeO2, SnO2, Sm2O3, TeO2, MoO3, Nb2O5, SiO2, CuO, CdO, HfO2, Pr2O3, and mixtures thereof. The dopants can be added to the ceramic composition in individual amounts ranging from 0.01 wt % to up to 5.0 wt %. The preferred ceramic compositions exhibit one or more of the following electromechanical properties: a relative dielectric constant (?) of between 1200 and 2000, a mechanical quality factor (Qm) of between 1500 and 2800; a piezoelectric strain constant (d33) of between 250-450 pC/N, a dielectric loss factor (tan ?) of between 0.002-0.

Abstract: Piezoelectric ceramics of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, and x is between 0.3 and 0.6, y is between 0.2 and 0.5, and z is between 0.04 and 0.08, wherein y=0.551?0.539x?0.593x2. The piezoelectric ceramic is provided as a composite perovskite structure, and may additionally include materials or dopants such as: PbO, HfO2, TeO2, WO3, V2O5, CdO, Tm2O3, Sm2O3, Ni2O3, and MnO2. The piezoelectric ceramics can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: A piezoelectric buzzer includes a vibrating layer capable of withstanding temperatures in excess of 260° C. for at least five minutes while still maintaining its ability to vibrate and produce a buzzing sound at a level of at least 80 dB, and a high temperature piezoelectric material having a Curie temperature in excess of 260° C. and one or more of the following properties: a planar coupling coefficient (kp) of at least about 0.5; a longitudinal coupling coefficient (k33) of at least about 1500; and a mechanical quality factor (Qm) of at least about 2000. The piezo material may have a combination of these properties such that the product (kp2)(k33)(Qm) is at least about 1.5×106. The piezoelectric material may have a base formula of PbxSr(1-x)(Mn1/3Sb2/3)(1-y)(ZrzTi1-z)yO3 with x ranging from 0.95 to 0.99, y ranging from 0.92 to 0.97, and z ranging from 0.45 to 0.55, and may further include dopants in the amounts of about 0.4% CeO2, about 1% CuO, and about 4% Nb2O5.

Abstract: Piezoelectric compositions of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, x is between about 0.35 and about 0.40, y is between about 0.36 and about 0.42, and z is between about 0.04 and about 0.08. The piezoelectric ceramic is provided as a composite perovskite structure. Additional materials or dopants can be added to the piezoelectric ceramic of the present invention. Example of dopants that can be added to the piezoelectric ceramic include, but are not limited to: MnO2, Ni2O3, TeO3, TeO2, MoO3, Nb2O5, Ta2O5, CoCO3, and Y2O3. The piezoelectric ceramics of the present invention can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: A class of ceramic compositions according to the formula Pb(1-z)Mz(Mn1/3Sb2/3)x(ZryTi1-y)1-xO3 where M is selected to be either Sr or Ba, x is selected to be between 0.01 and 0.1, y is selected to be between 0.35 and 0.55, and z is selected to be between 0.01 and 0.10. In some embodiments of the above composition, one or more dopants is added to the compositions. The dopant(s) may be selected from the group comprising: PbO, CeO2, SnO2, Sm2O3, TeO2, MoO3, Nb2O5, SiO2, CuO, CdO, HfO2, Pr2O3, and mixtures thereof. The dopants can be added to the ceramic composition in individual amounts ranging from 0.01 wt % to up to 5.0 wt %. The preferred ceramic compositions exhibit one or more of the following electromechanical properties: a relative dielectric constant (?) of between 1200 and 2000, a mechanical quality factor (Qm) of between 1500 and 2800; a piezoelectric strain constant (d33) of between 250-450 pC/N, a dielectric loss factor (tan ?) of between 0.002-0.

Abstract: Piezoelectric ceramics of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, and x is between 0.3 and 0.6, y is between 0.2 and 0.5, and z is between 0.04 and 0.08. The piezoelectric ceramic is provided as a composite perovskite structure, and may additionally include materials or dopants such as: PbO, HfO2, TeO2, WO3, V2O5, CdO, Tm2O3, Sm2O3, Ni2O3, and MnO2. The piezoelectric ceramics can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: This invention relates to a piezoelectric ceramic of the formula Pb(1?z)Mz(Mg1/3Nb2/3)x(ZryTi1?y)1?xO3 where M can be either Sr or Ba or both and x is in between about 0.1 and about 0.7, y is between about 0.2 and about 0.7, and z is between about 0.02 and about 0.1 and to method for preparing the piezoelectric ceramic. The piezoelectric ceramic is provided as a composite perovskite structure. Additional materials or dopants can be added to the piezoelectric ceramic of the present invention. Example of dopants that can be added to the piezoelectric ceramic include, but are not limited to: MnO2, Ni2O3, TeO3, TeO2, MoO3, Nb2O5, Ta2O5, CoCO3, and Y2O3. The piezoelectric ceramics of the present invention can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.