In one example, a method performed by electronic circuitry comprises: causing a transducer to transmit a first signal; receiving a second signal from the transducer; computing distances responsive to a time between the first and second signals; determining a vibration characteristic based on the distances; reading reference vibration characteristics from data in a memory; comparing the input vibration characteristic to the reference vibration characteristics; and responsive to the comparing, performing at least one of: providing a signal representing a status of the comparing; or updating the data in the memory.

The invention comprises a device and method to estimate the elasticity of soft elastic solids from surface wave measurements. The method is non-destructive, reliable and repeatable. The final device is low-cost and portable. It is based in audio-frequency shear wave propagation in elastic soft solids. Within this frequency range, shear wavelength is centimeter sized. Thus, the experimental data is usually collected in the near-field of the source. Therefore, an inversion algorithm taking into account near-field effects was developed for use with the device. Example applications are shown in beef samples, tissue mimicking materials and in vivo skeletal muscle of healthy volunteers.

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 phase-based approach can be used for one or more of acquisition, storage, or subsequent analysis, e.g., A-scan reconstruction or Total Focusing Method imaging, in support of acoustic inspection. For example, binarization or other quantization technique can be used to compress a data volume associated with time-series signal acquisition. A representation of phase information from the time-series signal can be generated, such as by processing the binarized or otherwise quantized time-series signal. Using the representation of the phase information, a phase summation technique can be used to perform one or more of A-scan reconstruction, such as for pulse-echo A-scan inspection, or a TFM imaging technique can be used, as illustrative examples. In such a phase summation approach, time-series representations of phase data can be summed, such as where each time-series can be delayed (or phase rotated) by an appropriate delay value and then aggregated.

A sensor with a mechanical waveguide may be characterized using test ultrasonic signals to generate a baseline signature, and the baseline signature may later be used to detect faults in the sensor.

Disclosed is a dual channel nondestructive testing method for a rock bolt and related devices. The method includes: determining a target phase difference and an instantaneous phase difference of the first received signal and the second received signal; determining an integral instantaneous phase difference between the first received signal and the second received signal based on the target phase difference and an instantaneous phase difference; determining a length of the exposed section of the rock bolt, a length of the rock bolt and a position of a grouting defect based on the integral instantaneous phase difference, a first velocity of the acoustic signal propagating in an exposed section of the rock bolt and a second velocity of the acoustic signal propagating in an anchor section of the rock bolt.

An active mechanical waveguide including an ultrasonically-transmissive material and a plurality of reflection points defined along a length of the waveguide may be driven at multiple resonant frequencies to sense environmental conditions, e.g., using tracking of a phase derivative. In addition, frequency-dependent reflectors may be incorporated into an active mechanical waveguide, and a drive frequency may be selected to render the frequency-dependent reflectors substantially transparent.

A method of detecting at least a partial blockage in a porous member separating an inner chamber of a device having a gas sensor responsive to an analyte positioned within the inner chamber and an ambient environment includes emitting pressure waves within the inner chamber and measuring a change in phase of a response via a sensor responsive to pressure waves.

A transmission probe for transmitting guided waves propagating in the longitudinal direction of a long member and a reception probe for receiving guided waves derived from the guided waves reflected from a predetermined portion of the long member are set on the long member. The guided waves received by the reception probe include a guided wave serving as a second signal that is noise of a desired first signal. The guided wave serving as the second signal having nodes in a circumferential direction distribution of displacement in a specific direction in the circumferential surface of the long member, and the guided waves transmitted by the transmission probe are formed such that the displacement of the guided wave serving as the second signal in the specific direction becomes zero at a specific circumferential surface position of the long member. A probe setting method comprising the steps of: setting the transmission probe for transmitting the guided waves on the circumferential surface of the long member; and setting the reception probe at a position at which the displacement of the guided wave serving as the second signal in the specific direction becomes zero on the circumferential surface of the long member.

A method for determining plane stresses on an in-service steel structure member based on phase spectrum of ultrasonic transverse wave, including: calibrating stress-spectrum parameters k and c of a replica of the in-service steel structure member; determining a first response frequency of a phase difference and a maximum value of a derivative function of the phase difference of an ultrasonic transverse wave echo of the in-service steel structure member, and obtaining a polarization angle of ultrasonic transverse wave components generated by a birefringence effect; solving a plane normal stress difference and a plane shear stress inside the in-service steel structure member; and separating normal stresses by a shear difference method to obtain three independent plane stress components.