In a measuring arrangement for determining properties of a material to be extruded while an extrusion process is being carried out in an extruder, at least one extruder screw is rotatably mounted in a tubular guide in a barrel and is connected to a rotary drive. Material to be extruded is fed to the tubular guide at one end and is removed as finish-extruded material at an oppositely arranged discharge. Arranged at measuring positions at predeterminable defined intervals on the wall of the tubular guide along the longitudinal axis of the extruder screw are multiple first sound transducers, which are designed for the detection of sound waves that are generated during the extrusion process by the extrusion process as process noises and/or are emitted by a second sound transducer, arranged at one end of the tubular guide, in the direction of the longitudinal axis of the extruder screw and into the material to be extruded that is conveyed through a mixing chamber present in the tubular guide.

Operating parameters are selected for inspecting a structure. Selecting the operating parameters includes exciting broadband ultrasonic guided waves in a multilayered structure, acquiring data corresponding to the sensed broadband ultrasonic guided waves in the multilayered structure, selecting one or more narrow frequency bands based on the acquired data, and inspecting the multilayered structure using ultrasonic guided waves in the one or more narrow frequency bands. In some examples, the data is acquired by an inspection tool capable of sensing the broadband ultrasonic guided waves in the multilayered structure.

Methods and devices are provided for analyzing a tubular structure including at least two electromagnetic-acoustic transducers (EMAT) and, called sensors, attachable or attached in, on or in the vicinity of the tubular structure; and computation and/or memory resources, that are accessed locally and/or remotely and that are configured to determine, for the pair of sensors, a function representing the impulse response of the tubular structure on the basis of the diffuse acousto-elastic noise present in the structure. Developments describe the use of rings supporting the sensors; translation and/or rotation movements; permanent or temporary installations; hinged rings; various computation modes, e.g., intercorrelation, a passive inverse filter, or correlation of the coda of the correlation; the use of artificial noise sources, imaging (e.g., tomography) for determining the existence of one or more defects in the structure. Software aspects are described.

A method is provided in which an ultrasonic signal is generated as an electromagnetic ultrasonic signal by the at least one transmitting transducer, which is in the form of an EMUS transducer, by means of a conductive layer arranged on the surface of the object or in said object. An evaluation apparatus is used to utilize the ultrasonic signal detected by the at least one receiving transducer, which is in the form of an EMUS transducer, in order to determine a flaw in the form of a delamination, a porefield or other such two-dimensional inhomogeneities.

An electro-magnetic acoustic transducer (EMAT) having an electromagnet array is provided. The electromagnet array includes electromagnets. Each electromagnet includes a magnetic core and a wound coil wrapped around the magnetic core. The electromagnet array generates bias magnetic fields having different patterns when the wound coils are energized differently. For instance, the electromagnet array generates a bias magnetic field having a given pattern, for the EMAT to transmit a first type of ultrasonic wave such as shear-horizontal wave, when the wound coils are energized in a given manner; and generates a bias magnetic field having a different pattern, for the EMAT to transmit a second type of ultrasonic wave such as a Lamb wave, when the wound coils are energized in a different manner.

A staggered magnet array (SMA) based electromagnetic acoustic transducer (EMAT) system and method for controlling the direction of the ultrasonic waves in the electromagnetic acoustic transducer (EMAT) using staggered magnet array (SMA) configurations, is disclosed herein. The EMAT device proposed herein comprises at least one conductive racetrack coil and at least two magnet arrays wherein the magnet array comprises of permanent magnets, where each magnet is oriented according to a specific configuration to produce ultrasonic waves in order to form an ultrasonic beam by shifting the position of the magnet arrays up or down creating a SMA configuration.

Embodiments include an electromagnetic acoustic transducer (EMAT) system. The EMAT system includes a plurality of magnets and a conductor set. The plurality of magnets has a like pole arrangement and wherein each magnet is in close proximity to one another. The conductor set includes electrically conductive elements. A portion of the conductor set is positioned proximate to the plurality of magnets. The plurality of magnets and the conductor set are positioned proximate to a test object. The EMAT system is configured to perform at least one of generating and receiving an elastic wave. Embodiments also include a method of elastic wave measurement for nondestructive testing and evaluation. The method includes the steps of positioning an EMAT proximate a test object, generating an elastic wave such that the elastic wave propagates about the test object, detecting the elastic wave propagating about the test object, and analyzing difference in elastic wave character between the elastic wave in the generating step and the elastic wave in the detecting step to evaluate the test object.

A magnetostrictive position measuring method determines a time of flight of a magnetostrictive response transmitted through a waveguide. The magnetostrictive response is generated using a target magnet in response to a magnetostrictive excitation. In the method, an electrical response signal containing an indicator of the magnetostrictive response is digitally sampled at a sampling rate to obtain a plurality of samples. An amplitude of each of the plurality of samples within a target frequency range is determined through an analysis of the plurality of samples in a frequency domain. A peak sample from the plurality of samples in the frequency domain corresponding to the magnetostrictive response is identified. The time of flight and a position of the target magnet along the waveguide is determined based on the peak sample.

A magnetoresistive acoustic wave sensor with high sensitivity and an array device thereof is disclosed, in which a magnetoresistive acoustic wave sensor comprises a protective tube shell, a magnetic vibration assembly, and a magnetoresistive chip located inside the protective tube shell. The protective tube shell comprises at least one opening which is covered by the magnetic vibration assembly. The plane where the magnetoresistive sensor chip is located is perpendicular to the plane where the magnetic vibration assembly is located, and the sensing direction of the magnetoresistive sensor chip is located in the plane where magnetoresistive sensor chip is located, and is perpendicular to or parallel to the plane where the magnetic vibration assembly is located. Alternatively, the plane where the magnetoresistive sensor chip is located is parallel to the plane where the magnetic vibration assembly is located, and the sensing direction of the magnetoresistive sensor chip is located in the plane where the magnetoresistive sensor chip is located, and is parallel to the plane where the magnetic vibration assembly is located. The magnetoresistive acoustic wave sensor with high sensitivity and an array device thereof is of small size, high sensitivity, low power consumption, high response speed, good stable temperature, large response frequency bandwidth, excellent low-frequency response and the like.

A system includes a scanner body, a sensor package, a magnet, an actuator mechanism, and a retention mechanism. The sensor package includes a ferromagnetic strip and a flexible coil configured to at least one of transmit and detect a guided wave. The magnet is for applying a biasing magnetic field to the ferromagnetic strip. The actuator mechanism is configured to provide a mechanical pressure coupling between the magnetostrictive strip and a structure, and the retention mechanism is configured to counteract a force applied by the actuator mechanism. A processor is in communication with the sensor package and is configured to record guided wave signals detected by the flexible sensor coil, record scanner body location data provided by a position encoder, and generate two-dimensional image data of an anomaly in the structure based on the guided wave signals and location data. Methods of use and operation also are disclosed.