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 methods and systems for determining a change in condition of a rock bolt. Some methods may comprise, at a first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a first time of flight for each of the shear and longitudinal waves, at a second point in time after the first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a second time of flight for each of the shear and longitudinal waves, and using the relative changes of the first and second time of flights, determining the change in condition of the rock bolt section.

A method of measuring a property of a medium using ultrasound, comprising: transmitting one or more ultrasound pulses into the medium from one or more transmitters and receiving at least a first echo signal and a second echo signal from within the medium at one or more receivers, wherein the first and second echo signals correspond to first and second pulse transmission paths within the medium from the one or more sources to the one or more receivers, the second path being different from the first path; and using the characteristics of the first and second echo signals together with an estimate of the property of the medium and a geometrical relationship between the first and second transmission paths to calculate a revised estimate of said property of the medium. By using two different beam paths within the medium, the first and second echoes will have had slightly different interactions with the medium. For example the different paths may well have different lengths thus giving different amounts of interaction such as different amplitude or phase effects on the different pulses. By comparing the similarities and differences between the pulses, certain properties of the medium can be discerned. Many different properties can be investigated using these principles. In particular, the speed of sound in a medium can be measured and the direction and magnitude of a flow or particle movement within the medium can be measured. An iterative process may be used.

Methods and devices are provided for detecting, corrosion and cracks in fastener nuts. In an exemplary embodiment, an apparatus can be configured to couple to a fastener nut to facilitate inspection of the fastener nut for detection of flaws in the fastener nut, such as corrosion and cracks. The apparatus can be configured to couple to the fastener nut when the fastener nut is mounted on a fastener and in use in a larger system such as a subsea drilling apparatus or other system in which fasteners with fastener nuts attached thereto are used. The apparatus can include an ultrasonic probe configured to facilitate inspection of the fastener nut using ultrasonic waves.

An improved ultrasonic waveguide for an ultrasonic thermometry system is provided. The waveguide includes a series of sensing zones, each of which is tuned to a specific narrow frequency band. The waveguide is acoustically coupled to a transducer, which launches a longitudinal elastic wave of desired waveform and frequency. The wave propagates down the waveguide, and is reflected from the sensing zone that is tuned to that frequency. Each sensing zone is designed to be highly reflective to a narrow frequency band while being transparent to other frequencies.

The disclosure discloses a stress gradient high-efficiency non-destructive detection system based on frequency domain calculation of broadband swept frequency signals, and a detection method thereof. The detection method includes: step 1: calibrating an LCR wave velocity of an object to be measured; step 2: calculating a starting frequency and a cut-off frequency of broadband swept frequency signals based on the LCR wave velocity of the object to be measured in the step 1 and a stress gradient measuring range in a depth direction of the object to be measured; step 3: converting phase delay to time delay information based on the phase delay of the starting frequency and the cut-off frequency in the step 2; and step 4: determining stresses of depths corresponding to different frequency components based on the time delay information in the step 3 to finally realize layer-by-layer scanning of stresses at different depths of the measured object. The disclosure is used to solve the problem of low stress gradient measuring accuracy, and realize the high-efficiency characterization of the stress gradient in the depth direction.

A fluidic device includes at least one bulk acoustic wave (BAW) resonator structure with a functionalized active region, and at least one first (inlet) port defined through a cover structure arranged over a fluidic passage containing the active region. At least a portion of the at least one inlet port is registered with the active region, permitting fluid to be introduced in a direction orthogonal to a surface of the active region bearing functionalization material. Such arrangement promotes mixing proximate to a BAW resonator structure surface, thereby reducing analyte stratification, increasing analyte binding rate, and reducing measurement time.

A device for testing a test material for defects within the test material has an acoustic broadband transducer offset from the test material surface during testing by a distance so that the transducer acquires acoustic waves across an air gap from the test material, wherein the acoustic waves arise from impact of an impact member on the test material.

A method for detecting residual stress induced by cold expansion (Cx) (Cx stress) at a hole in a structure. Two transducer pairs transmit and receive ultrasonic waves into the structure in a pitch-catch configuration along two first paths parallel to a tangent of the hole. The two paths are at different distances from the hole. Both transducer pairs are arranged such that their incident angle into the structure provides longitudinal critically refracted (LCR) waves within the structure. Time-of-flight (ToF) measurements of the LCR waves along the first path and the second path are the basis of acoustoelasticity calculations that determine if Cx stress is present at the hole.

Non-destructive inspection device, comprising: a first structural layer; a second structural layer coupled to the first structural layer; a chamber sealed between the first and second structural layers, containing a gas; and an active region, housed in the chamber, of a Graphene-based material. In a first operating condition, an AC electric current is fed to the active region and generates by thermoacoustic effect a first acoustic wave propagating away from the chamber. In a second operating condition, a second acoustic wave, generated by a reflection of the first acoustic wave, is received at the chamber and causes a variation in pressure and, consequently, a variation in the temperature of the gas contained in the chamber generating, by means of the thermoelectric effect, an electrical signal in the active region.