Abstract: A transducer-based sensor system including a drive signal generator for generating a drive signal, a transducer coupled to the drive signal generator and configured to receive the drive signal, a mixer coupled to the transducer and configured to receive output from the transducer where such output results at least in part from physical movement of the transducer, and a diplexer operatively coupled with an output of the mixer and configured to present a substantially matched output impedance to the mixer over an operative range of output frequencies.

Abstract: A method for inspecting pipe, the method, in at least certain aspects, including detecting an inspection parameter in at least a first part of a pipe, the pipe having a length, a hollow body, an outer surface, and a generally circular pipe wall with an inner diameter and an outer diameter, locating at a first location the first part of the pipe with respect to the length of the pipe and with respect to the outer diameter of the pipe; and such a method for inspecting pipe which, in at least certain aspects, includes detecting at least a first part of a first imperfection of the pipe.

Abstract: A method and system for determining meat quality in cattle is provided. In preferred embodiments the method comprises obtaining an ultrasound measurement of a cattle specimen between the 12th rib and 13th rib at weaning age. The ultrasound measurement is utilized to extrapolate a harvest quality parameter. Based on the harvest quality parameter, and preferably a yield grade, the specimen is categorized. Particularly preferred harvest quality parameters are ribeye area, fat thickness, intramuscular fat and ribeye shape. Methods for determining tenderness, stress and intramuscular fat are described and claimed.

Abstract: A method and apparatus for analyzing a deposited layer on the inner surface of a fluid container wall having inner and outer surfaces are disclosed. One embodiment of the method comprises (a) transmitting an acoustic signal from a transmitter at a first distance from the outer surface of the wall; (b) receiving a first received signal A, comprising a reflection from the wall outer surface; (c) receiving a second received signal B, comprising a reflection from the wall inner surface; (d) receiving a third received signal C from the wall inner surface; (e) calculating a coefficient Rwp from A, B and C, and (f) calculating a coefficient Rpd from A, B and Rwp, and calculating the acoustic impedance of the deposited layer Zd from Rwp, Rpd, and Zw, where Zw is the acoustic impedance of the material between the transmitter and the wall outer surface.

Abstract: The present invention provides a system and method for measuring the surface properties of polishing pads using noncontact ultrasonic reflectance. An ultrasonic probe is located over the polishing surface and configured to both transmit an ultrasonic signal to the polishing surface and receive a modified ultrasonic signal from the polishing surface without contacting the polishing surface. A subsystem coupled to the ultrasonic probe is configured to determine a surface property of the polishing pad from the modified signal.

Abstract: A filling level measuring device with a transmitting and receiving device (1) and a waveguide (6, 7), one end of which (6a, 7a) is coupled to the transmitting and receiving device (1) and the other end of which (6b, 7b) is immersed in a filling material (11), to which waveguide (6, 7) electromagnetic waves from the transmitting and receiving device (1) can be conducted, while electromagnetic waves reflected in the waveguide (6, 7) can be used in the transmitting and receiving device (1) for measuring the filling level, and the other end (6b, 7b, 28b) exhibits a wave absorption device (26, 27, 29, 17, 18, 22) for at least partial absorption of the conducted electromagnetic waves.

Abstract: A measurement head for a device for measuring the level of a product in a container comprises a transmitter/receiver unit to transmit a scanning signal and receive an echo of the scanning signal returned by the product, a fastening element to fasten the transmitter/receiver unit to a support and at least one actuator to move the transmitter/receiver unit relative to the fastening element.

Abstract: An improved plunger for fluid dispensing cartridges used in automated dispensing systems. The plunger helps control the reflection of ultrasonic signals used to sense the position of the plunger as it moves within the cartridge tube. The plunger has a convex bottom, ink-facing surface and a top surface comprising one or more flat, horizontal surfaces. In the preferred embodiment, the horizontal surfaces are concentric steps.

Abstract: An inclination angle measurement apparatus includes a first ultrasonic sensor (3) for sending an ultrasonic wave toward a reflective object (2), second and third ultrasonic sensors (4 and 5) each for receiving an ultrasonic wave reflected from the reflective object (2), and a calculation control circuit (14) for calculating an angle of inclination of a moving object with respect to the reflective object (2) based on a phase difference between ultrasonic waves received by the second and third ultrasonic sensors (4 and 5). Thus the inclination angle measurement apparatus can accurately measure the angle of inclination of the moving object with respect to the reflective object (2).

Abstract: An ultrasonic inspection device is constructed of an ultrasonic scanning unit, drive unit for the ultrasonic scanning unit, and a computing unit. The ultrasonic scanning unit is provided with an ultrasonic probe for two-dimensionally scanning a surface of a specimen with an ultrasonic wave through a medium such as water for the ultrasonic wave. The computing unit controls the ultrasonic scanning unit via the drive unit and performs an inspection for any flaw in a film formed on a surface of abase material as the specimen. From the ultrasonic probe to the specimen, an angled incident wave is transmitted such that a leaked elastic surface wave is induced, and a leaked wave from the specimen is received at the ultrasonic probe. When the adhesion is good, the reception level of the leaked wave becomes low. When the adhesion is poor, on the other hand, the reception level of the leaked wave becomes high.

Abstract: An ultrasonic pulse/echo measurement arrangement includes an ultrasonic transducer (12), which is mounted spatially fixed on an air spring cover plate (4). The arrangement further includes a fixedly mounted reference reflector (14), a target reflector (16) mounted on a roll-off piston (8) or on the buffer (18) as well as a transmitter/receiver evaluation electronic circuit (30). The running time as well as the amplitude of the reference signal is evaluated to precisely determine the pressure present in the interior space of the air spring. The ultrasonic transducer (12) has a &lgr;/4-adaptation layer (22), whose impedance does not correspond to the geometric mean of the impedances of the ultrasonic transducer (12) and the ambient air of the interior space (20) of the air spring, but rather, is a mismatch. The evaluation electronic circuit (30) can be calibrated at ambient pressure for the determination of the inner pressure of the air spring.

Abstract: A system for monitoring deformations of a moving tyre mounted on a rim associated with a vehicle includes a moving station and a fixed station. The moving station is operatively coupled to the rim. The moving station measures, at least intermittently and in at least one direction, a distance between the moving station and an inner surface of the tyre. The fixed station is operatively coupled to the vehicle. The fixed station receives from the moving station, at least intermittently, at least one first signal associated with the measurement. The moving station measures the distance within a time interval when a first antenna associated with the moving station and a second antenna associated with the fixed station are in proximity to each other. Related methods for monitoring deformations of a moving tyre mounted on a rim associated with a vehicle are also disclosed.

Abstract: An ultrasonic testing method to evaluate the structural integrity of lead-acid batteries terminal posts including the steps of transmitting ultrasonic waves from a transducer through the body of the lead-acid battery posts, detecting the internal defects in the terminal posts by a reflected echo from the internal defect, and deciding to reject or to accept a lead-acid battery by comparing and analyzing, through hardware and software, the transmitted and reflected ultrasonic waves of the bad terminal posts against the reference of transmitted and reflected ultrasonic signal of a good terminal post. The internal defects detected by this method are pores, flaws, and cracks.

Abstract: A method and apparatus for analyzing a deposited layer on the inner surface of a fluid container wall having inner and outer surfaces are disclosed. One embodiment of the method comprises (a) transmitting an acoustic signal from a transmitter at a first distance from the outer surface of the wall; (b) receiving a first received signal A, comprising a reflection from the wall outer surface; (c) receiving a second received signal B, comprising a reflection from the wall inner surface; (d) receiving a third received signal C from the wall inner surface; (e) calculating a coefficient Rwp from A, B and C, and (f) calculating a coefficient Rpd from A, B and Rwp, and calculating the acoustic impedance of the deposited layer Zd from Rwp, Rpd, and Zw, where Zw is the acoustic impedance of the material between the transmitter and the wall outer surface.

Abstract: A method and apparatus for analyzing a deposited layer on the inner surface of a fluid container wall having inner and outer surfaces are disclosed. One embodiment of the method comprises (a) transmitting an acoustic signal from a transmitter at a first distance from the outer surface of the wall; (b) receiving a first received signal A, comprising a reflection from the wall outer surface; (c) receiving a second received signal B, comprising a reflection from the wall inner surface; (d) receiving a third received signal C from the wall inner surface; (e) calculating a coefficient Rwp from A, B and C, and (f) calculating a coefficient Rpd from A, B and Rwp, and calculating the acoustic impedance of the deposited layer Zd from Rwp, Rpd, and Zw, where Zw is the acoustic impedance of the material between the transmitter and the wall outer surface.

Abstract: A method and system are disclosed for monitoring vacuum integrity in a vacuum interrupter. The method includes injecting sonic signals into a body and detecting sonic signals reflected from the body. A composite value is calculated from the reflected sonic signals and a determination made based on the composite value as to whether the vacuum is acceptable. The system includes the following components: a transducer for sending sonic signals into a body; a receiver for receiving sonic signals reflected from the body; a signal processor for calculating a composite value from the sonic signals reflected from the body; and a processing unit for determining from the composite value whether the body has an acceptable vacuum therein.

Abstract: An ultrasonic ice detector that can be mounted directly to the skin of an aircraft includes a transducer that is coupled to the interior surface of the skin, and transmits acoustic vibrational energy through the skin. A reflector bar having a reflector surface is mounted on the interior surface of the skin at a location spaced from the transducer and is effective to reflect acoustic energy back to the transducer. The reflector bar is raised from the interior surface and preferably has a width equal to the width of the acoustic wave that is generated by the transducer at the reflector location. The transducer and reflector are non-intrusive and do not alter the aircraft skin structural integrity. The arrangement provides an accurate, responsive sensor for determining presence of ice or other contaminants on the exterior surface of the skin.

Abstract: A novel method of non-destructive die crack inspection of a plastic encapsulated integrated circuit (PEIC) uses a scanning acoustic microscope, such as a C-mode scanning acoustic microscope. To generate scan of a die surface of the PEIC, the width of a data gate of the microscope is set to scan only the die surface. Then, the data gate is moved to cover only die subsurface reflection area on a screen of the microscope, and scan of the die subsurface is generated.

Abstract: A system and a method are provided for monitoring the condition of an interface. Although not limited to this particular application, the system and method are particularly suited for monitoring the interface of two liquid lubricated mechanical seal faces. The system monitors an interface by using a wave source to produce an ultrasonic shear wave, directing the wave at the interface, detecting the wave after it interacts with the interface, and comparing the detected wave to predetermined wave characteristics. Based on the comparison, an alarm may be triggered. The alarm may indicate that the mechanical seal is failing.

Abstract: Apparatus for detecting an interface (13) between two media of a heterogeneous system, comprising transmission means (21) to send a signal through one medium from the transmission means (21) to the interface (13), measuring means (32b, 32c, 32d) to measure the time taken for the signal to be reflected to a reception means (36), and processing means (40c, 40d) to use said time to determine the distance of the interface from the transmission means.

Abstract: A flaw detection system using acoustic Doppler effect for detecting flaws in a medium wherein there is relative motion between the medium and system includes a transducer, spaced from the medium to be inspected, for introducing to and sensing from the medium an acoustic signal that propagates in the medium at a predetermined frequency; and a detector, responsive to the sensed propagating acoustic signal, for detecting in the sensed acoustic signal the Doppler shifted frequency representative of a flaw in the medium.

Abstract: Cleanliness of a metallic material to be tested is provided. The method includes the steps of setting n inspection fields in predetermined portions of the metallic material to be tested, scanning each inspection field by ultrasonic flaw detection method for non-metallic inclusions in the metal thereby to determine the maximum non-metallic inclusion diameter aj (j=1,n), and calculating the estimated maximum non-metallic inclusion diameter amax in the metallic material to be tested from the maximum non-metallic inclusion diameter aj (j=1,n) determined for each inspection field, thereby evaluating the cleanliness of metallic materials quickly with high accuracy and high reliability.

Abstract: Method, apparatus and computer programs are described for compensating for the effect of temperature on the sensitivity of electrostatic ultrasound (US) transducers, particularly as used in an automotive occupancy sensing (AOS) systems for sensing the nature or type of occupant and the location of the occupant with respect to the vehicle interior. The invention permits the AOS to classify the occupancy state of the vehicle from a US echo signal substantially free of the effects of temperature on signal amplitude. A capacitive divider or voltage monitor is employed to measure the capacitance of the transducer. The voltage monitor output is used by the scaling algorithm of a compensator to determine the scaling factor to be applied to the US transducer signal to compensate for the effect of temperature on the transducer sensitivity.

Abstract: A vehicle exterior object detector apparatus includes a transceiver carried within an optically clear housing and mounted by a holder to a support on the vehicle. A potting compound surrounds the transceiver within the optically clear housing, the potting compound having a cure time less than that of a heat curable potting compound. A heater element is carried in the holder in surrounding relationship with one end of the transceiver housing for melting ice and snow build up on the end of the housing for proper operation of the transmitter and receiver.

Abstract: A gauge for determining a thickness of a coating on a substrate includes a transducer for emitting ultrasonic signals into the coating and for generating electrical signals proportional to the ultrasonic signals received by said transducer, said received signals include first signals reflected from a transducer/coating interface and second signals reflected from a coating/substrate interface; a pulser for sending pulses to the transducer to trigger the emission of said ultrasonic signals; a sampler for sampling the electrical transducer signals and generating sampled data; a timer for controlling the pulser and the sampler so as to perform an equivalent time sampling of the signals received by the sampler; and a controller for calculating a thickness of the coating based on said sampled data, said controller includes the ability to subject said sampled data to a deconvolution analysis so as to distinguish sampled data corresponding to said first signals from sampled data corresponding to said second signals w

Abstract: A semiconductor post-polishing processing apparatus and method employing a non-optical wafer sensor for detecting the presence of a semiconductor wafer within the processing stations. The apparatus comprising a wet processing station, a wafer transport track, and the non-optical sensor. Preferably, the non-optical wafer sensor is a transducer, and most preferably, a piezo element, which emits and detects sound waves. The sound waves are reflected back to the emitter signaling the presence of a semiconductor wafer. The signal is sent to a receiver linked to a processor which is adapted to move a wafer holder situated at the end of the transport track to receive a wafer in the next available empty slot of the holder. The non-optical wafer sensor is impervious to slurry and CMP residue, film build-up, bubbles, wafer color/hue variations, and other wet environment problems.

Abstract: An ultrasonic pulse echo inspection apparatus and method for detecting structural failures. A focus lens is coupled to the transducer to focus the ultrasonic signal on an area to be inspected and a stop is placed in the focus lens to block selected ultrasonic waves. Other waves are not blocked and are transmitted through the structure to arrive at interfaces therein concurrently to produce an echo response with significantly less distortion.

Abstract: The invention is directed to an air spring arrangement having a device for making ultrasonic distance measurements. An ultrasonic sensor, which is built into an air spring (2) for making measurements, can be disturbed when high frequency sonic oscillations occur when filling and venting the air spring. An air supply line (8) is disposed between the air spring (2) and a source of compressed air (30). To prevent the above disturbing frequencies, the air supply line (8) includes an air connecting pipe stub (10) which is lined with a net-shaped layer (16) on its inner wall surface. The layer (16) is preferably a plastic mesh. The filaments (18) of the mesh-shaped layer (16) are slightly inclined to the longitudinal center axis (28) of the pipe stub (10).

Abstract: A method and apparatus for measuring characteristics of meat, such as beef. More particularly, the invention uses quantitative analysis of ultrasonic A scan signals to measure the following characteristics of meat in real time: the percentage of intramuscular fat, the quality grade, the merit number, the depth of back fat, the depth of the rump fat, and the body composition (yield grade). The ultrasonic A scan signals are measured above the twelfth rib, above the thirteenth rib, between the twelfth and thirteenth ribs, and in the rump area. The invention can be used with either live or processed animals.

Abstract: A plate (12) or pipe wall is inspected by coupling an ultrasonic transducer (14, 16) to its surface so as to generate a compression wave or lateral wave (26) along the surface and a shear wave or head wave (28) along the surface and a shear wave or head wave (28) at the shear-compression critical angle (.theta..sub.c) The same transducer (14, 16), or an additional transducer (15, 16) also coupled to the surface, detects a series of ultrasonic peaks corresponding to each generated ultrasonic pulse. Each such detected peak corresponds to ultrasonic energy traveling, partly as lateral waves (26, 32) on one surface or the other, and partly as head waves (28, 30) crossing a certain number of times between the surfaces. The transducers (14, 15) may be over 0.5 m apart, and substantially all the intervening parts of the plate (12) are inspected.

Abstract: A method and apparatus for nondestructive inspection of packaged integrated circuits and defect detection in the integrated circuits. In a scanning acoustic microscopy system, a packaged integrated circuit under test 31 is placed in a tank containing an acoustic transmission medium such as de-ionized water. An acoustic reflector 29 is placed beneath the integrated circuit 31. A pulse-echo mode transducer 17 is used to scan the area containing the integrated circuit 31 with ultrasonic energy. The reflective signal energy is captured by the transducer 17 and the signals are digitized and stored. A computer system analyzes the reflective signal amplitude, and presents a visual image based on where the reflective signal was strong and where it was weak. In a preferred embodiment the image is presented so that the signal from the reflective plate is shown as a dark region where the reflection was weak or zero.

Abstract: To permit immersion ultrasonic testing of a semiconductor processing component manufactured of porous metal, a cover is sealed over the processing surface of the component. The cover creates an acoustically reflective air gap between the cover and the processing surface. Ultrasonic waves scanned across the component reflect from this gap, creating an image of the internal structure of the component.

Abstract: The exact spring height as well as the spring pressure can be determined with a single arrangement for the optimal utilization of the axle loads of a multi-axle air spring suspended vehicle and to control the distance between the chassis and the axle. An air spring (2) is equipped with an ultrasonic pulse/echo measuring system. The air spring (2) includes a transmitter/receiver component (14) arranged on the chassis and a first reference electrode (20) and a reflector component (16) fixed to the axle. The air spring height can be determined in a conventional manner from the relative value of the running times of the ultrasonic pulses which are traversed on the reference path and the measuring path. A second reference reflector (22) is mounted at a different distance to the first reference reflector (20).

Abstract: A damaged turbine rotor wheel dovetail is repaired by cutting off the annular dovetail and welding a new forged ring onto the remaining wheel body. Fine-line welding is accomplished by inserting welding apparatus into grooves opening through axial faces of the wheel body and ring and rotating the rotor to provide multiple welding passes. Periodic ultrasonic inspection of the welds is provided by applying an ultrasonic transducer to the periphery of the ring to detect defects in the weld. To enable the transducer to operate at high welding temperatures, a manifold is disposed about the transducer defining a coolant cavity. Cooling medium is supplied the coolant cavity to maintain the transducer operable within predetermined temperature operating limits.

Abstract: The invention is directed to an arrangement for making contactless distance and pressure measurements within an air spring. With a single arrangement, the exact elevation of the spring as well as the spring pressure can be determined. This permits optimal utilization of the axle loads of a multi-axle vehicle and permits adjustment of the distance between the chassis and the axle. In the arrangement, an ultrasonic configuration makes contactless distance measurements in accordance with the pulse/echo method. The arrangement includes a transmitter/receiver component (4) mounted on the chassis and a first reflector (24) defining a first reference distance (16) therebetween. The component (4) and a reflector (6) define a measuring distance (30). The reflector (6) is fixedly mounted to the axle. The transmitter/receiver component (4) is elastically supported by a suspension (10) in a pipe stub (8) fixedly mounted to the chassis.

Abstract: An ultrasonic imaging system including an aberration correction system uses a harmonic component of the fundamental transmitted frequency for imaging, or for aberration correction, or both. By properly selecting the frequency pass bands of filters used in the image signal path and in the aberration correction signal path operating advantages are provided. The aberration correction values may be calculated concurrently with image formation.

Abstract: An ultrasonic transceiver has a function of displaying a modified B scope. The ultrasonic transceiver transmits ultrasonics to an inner part of a test object at an angle of inclination to a surface of the test object, receives echoes from discontinuity in the test object, and displays, based on an outcome of the reception, an image which shows a state of transmission of the ultrasonics in the test object. When displaying the image, origins of time axes on the screen are shifted through a coordinate transformation of the outcome of reception to avoid the difference in lateral positions of images of single discontinuity. Consequently, it is possible to accurately discern the location, size, configuration, and posture of the discontinuity when the outcome of reception is displayed in a rectangular display window.

Abstract: Radially spaced calibration holes are drilled parallel to the exterior surface of a cylindrical shell for a dryer roll. An ultrasonic transducer is mounted in a fixture filled with a coupling medium which allows for adjustment of the spacing and angle of the transducer which traverses the shell as it is rotated. The transducer produces a signal directed to the shell. A computer calculates the time the signal takes to travel from and return to the transducer and the depth of the shell from which the signal returns. A clear signal corresponding to holes up to one inch from the surface are found by adjusting the ultrasonic transmission angle. This angle is approximately 23 degrees from a normal to the casting surface. The calibrated transducer traverses the surface of the shell. The signals are gathered and stored to create data which may be used in maintaining the shell for the dryer roll.

Abstract: In an ultrasonic probe, an acoustic matching layer, which is fixed on the front side of a transducer for transmitting an ultrasonic wave and receiving a reflected wave thereof and matches in acoustic impedance the transducer to a living tissue in an object to be examined, is formed in such a structure that the acoustic impedance thereof is varied continuously in the thickness direction from the transducer to the object to be examined.

Abstract: An exemplary apparatus for determining the thicknesses of individual layers in a multilayer article comprises an ultrasonic transducer coupled to the multilayer article with a buffer rod of similar acoustic properties, a pulser-receiver-amplifier which generates ultrasonic waves to produce discernible, time resolved pulse echoes, a digitizing oscilloscope which may be used to view the received pulse echoes, and a computer for controlling data acquisition and analysis.

Abstract: An ultrasonic method to measure silver sheath thickness in silver sheathed, ceramic powder core High Temperature Superconductor (HTS) wires and an associated sensor system which is designed and developed for continuous, on-line, real-time measurement during wire drawing.

Abstract: A process using ultrasonic inspection for testing the internal soundness of cathode sputtering targets, whose active part is made of aluminum with a very high degree of purity or a very pure aluminum alloy, consisting, after selection of an ultrasound sensor functioning at an operating frequency greater than 5 MHz, preferably between 10 and 50 MHz, and adjusting the appropriate measurement sequence, using a target immersed in a liquid and which has ceratin artificial defects simulating decohesions in the target, taking a count in terms of size and number of the internal decohesions per unit volume and selecting, for the applications requiring a very high degree of etching fineness, the targets with a decohesion density of .ltoreq.0.1 decohesion larger than 0.1 mm/cm.sup.3 of active metal of the target, and cathode sputtering targets selected according to the process having no more than 0.1 internal decohesion larger than 0.1 mm/cm.sup.3 of active metal of the target.

Abstract: When an ultrasonic transducer for detecting discontinuities and/or delaminations in a thin layer of coated material applied to a metal plate or the outside wall or surface of a cast iron dryer cylinder is directed at the coated surface to be inspected at a particular angle, about 10 percent of the single will appear as Harris waves which propagate into the coated test plate at 90 degrees to the surface. This signal which propagates vertically is polarized, with the result that the signal has a greatly improved signal-to-noise ratio. For incident medium of Lucite and employing shear wave refracting in the medium of Lucite, the specific angle is approximately 66 degrees from the vertical for best signal-to-noise ratio. Shear or longitudinal waves can be employed to affect the detection of subsurface defects with the particular angle changing depending on the relation of the velocity of the sound waves in the refracting medium to the velocity of sound waves in the incident medium.

Abstract: A non-contact apparatus for monitoring the contents of a container, especially but not exclusively for quality control monitoring purposes associated with high speed packaging processes, comprises a non-contact ultrasound generation member, adapted so as to generate an ultrasound signal within the container (1). A non-contact detection scheme is employed to enable the contents of the container to be monitored by analysing ultrasound signals that have propagated through or round the container (1) either transmitted through or reflected from the containers contents. In use, the apparatus may be adapted to provide information about container fill level (h) or the presence or absence of an insert (14) such as a head forming device by analysing the measured signal profiles generated by a ultrasound detection member (3).

Abstract: A loading control system for a centrifuge used in, for example, a sugar refining operation, optimizes the introduction of product to be centrifuged. A loading system has an ultrasonic loading probe, a sound tube for delivering the sound signals to the sugar wall and returning to the ultrasonic probe, an analog controllable feed valve and a programmable logic controller which is used to control the operation. The logic program implements a control loop which analyses the signal from the probe and controls the position of the gate accordingly. Preferably, the system also implements a control loop for automatic adjustment of the flow rate and amount of sugar in the machine in order to optimize the loading process.

Abstract: The present invention is directed to a blown film extrusion apparatus in which film is extruded as a tube from an annular die and then pulled along a predetermined path. The improved blown film extrusion apparatus includes a system for gauging and controlling the surface of the extruded film tube, which includes a number of components which cooperate together. At least one transducer is provided and positioned adjacent the extruded film tube for transmitting interrogating pulses to, and receiving interrogating pulses from, the extruded film tube, and for producing a signal corresponding to a detected position of the extruded film tube. A control system is provided for substituting a filtered position signal derived from a dynamic filtering process in lieu of the detected position signal. An air flow controller is provided for varying a quantity of air within the extruded film tube in response to the control system for urging the extruded film tube to a desired position.

Abstract: In order to optimize an ultrasound measurement signal application-specifically, an error value is formed from features with which an evaluation of the received ultrasound measurement signal is possible. An ultrasound signal, whose signal shape is modified by section-by-section variation of the shape of the transmission signal is emitted out, received and an error value is formed anew. This procedure is repeated until the error value assumes a minimum. The ultrasound measurement signal at which the error value is minimal corresponds to the optimized signal.

Abstract: A device for the detection of smooth surface lesions of dental caries on a tooth crown surface, having an ultrasonic transducer for transmitting ultrasonic waves and receiving ultrasonic wave reflections produced by lesions present on the surface, and an interface operatively connected to the transducer. The interface has a contact surface forming an angle .alpha. with a longitudinal axis of the ultrasonic transducer, where .alpha. is substantially different from 90.degree.. When the contact surface is in at least partial contact with a tooth crown surface at the longitudinal axis, ultrasonic waves generated by the ultrasonic transducer are imparted by the interface onto the tooth crown surface as surface ultrasonic waves which migrate along the tooth crown surface. Any lesions present on the tooth crown surface are then identifiable as surface ultrasonic wave reflections produced thereat.

Abstract: An inflator for an airbag system has a target mounted in the pressurized gas contained in the inflator. An ultrasonic transducer is mounted on an external surface of the inflator in alignment with the target. The transducer generates and receives reflected ultrasonic signals from the target. The time-of-flight of the signals which are dependent on the gas pressure are used to determine the gas pressure in the inflator. Temperature compensation is provided by fabricating the target of bimetallic material which changes the spacing of the target from the transducer with temperature or providing a temperature sensitive element, e.g. a thermocouple to electrically provide temperature compensation.

Abstract: A non-destructive method and apparatus for determining the thickness of individual layers of different materials in a multilayer structure particularly useful in analyzing the layers in a multilayer plastic fuel tank, utilizes a constant and relatively high frequency ultrasonic pulse transmitted into the multilayer structure and records the time when interference pulses are received to determine the thickness of the individual layers in the multilayer structure. The interference pulses are generated at the interface between adjacent layers of sufficiently different materials and thus, the time between interference pulses is a function of the amount of time needed for the ultrasonic pulse to pass through a layer of material.