The embodiments disclosed herein relate to the examination of gemstones including diamonds, both cut/polished and rough, using the technology of Resonant Ultrasound Spectroscopy. The resonant frequencies are obtained by mechanically causing the stone to vibrate using a swept sine oscillator, sensing the resonance vibrations, and displaying the spectrum to yield a pattern describing the stone. The resonance fingerprints can be used to both track an individual stone to verify its integrity or to grade a rough stone to establish potential value.

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.

There is provided a method for determining material properties in an active acoustic spectroscopy system, the method comprising: acquiring a multidimensional acoustic spectrum from a material in a container using acoustic spectroscopy; reducing the dimensionality of the acoustic spectrum using a mathematical dimensionality reduction method, thereby forming a reduced acoustic spectrum describing a material state; and determining if the material state belongs to a predetermined material state cluster. There is also provided a system for performing the described method.

An ultrasonic inspection apparatus includes: an acquisition unit acquiring a signal indicating a fundamental wave and a second harmonic of an ultrasonic wave, which are obtained by the ultrasonic wave being scanned over an inspection object through a medium, at each scanning position; a calculation unit calculating a value obtained by dividing a second harmonic amplitude by a square of a fundamental wave amplitude, at each scanning position; and an output unit outputting information on a defect of the inspection object, based on the value obtained by dividing the second harmonic amplitude by the square of the fundamental wave amplitude.

A defect inspection device (100) includes an excitation unit that excites an elastic wave, an irradiation unit (2) that applies laser lights, a measurement unit (3) that measures the interfered laser lights, and a control unit that acquires vibration state information which is information about a state of the elastic wave excited in an inspection target (P) for a plurality of frequencies by changing a frequency of excitation vibration caused by the excitation unit in order to excite the elastic wave in the inspection target (P), and extracts recommended frequencies (F) recommended for inspecting a defect of the inspection target (P) from among the plurality of frequencies based on the acquired vibration state information for the plurality of frequencies.

The disclosure discloses an air-coupled ultrasonic detection method and device based on a defect probability reconstruction algorithm. The method includes the following steps: determining the excitation frequency of a transmitting air-coupled transducer according to a frequency dispersion curve of guided waves and the thickness of a to-be-detected piece; determining the group velocity of an antisymmetric mode according to the excitation frequency, and determining the inclination angle of the transmitting/receiving air-coupled transducer according to the Snell law; obtaining an initial waveform of a defect-free test piece as reference data by adopting a same-side penetration method, then rotating the transmitting/receiving transducer by 360 degrees by taking the Z direction as an axis at preset angle intervals by adopting a rotary scanning method, collecting N groups of signal data of the to-be-detected piece again, comparing the N groups of signal data with the reference data to determine whether the signal characteristics have great changes or not, calculating the defect distribution probability on the to-be-detected piece, and carrying out defect imaging on a rotating coverage area of the transmitting/receiving air-coupled transducer according to the defect distribution probability. According to the method, the precision of traditional air-coupled ultrasonic X and Y scanning detection is improved, and compared with a complex imaging technology, the air-coupled ultrasonic detection method consumes less time.

A sensor system includes one or more sensors that sense vibrations of a vehicle and one or more processors that can determine a speed of the vehicle and determine whether the vibrations occurring at one or more frequencies of interest (that are based on the speed of the vehicle) indicate damage to a propulsion system of the vehicle. The one or more processors optionally may determine a hunting frequency of a wheel and axle set and/or a lateral acceleration of the wheel and axle set from the vibrations. The one or more processors can determine a conicity of a wheel in the wheel and axle set based on the hunting frequency and/or the lateral acceleration that is determined.

An ultrasonic inspection method in which a pulse signal is output to an ultrasonic sensor to generate and transmit ultrasonic waves, the ultrasonic waves reflected or scattered by an object are received and converted into a waveform signal by the ultrasonic sensor, and the waveform signal is digitized to acquire waveform data, includes: executing modulation processing for modulating a plurality of waveform data acquired in multiple inspections and under the same inspection conditions by a phase modulation method to generate composite waveform data; and executing demodulation processing for demodulating the composite waveform data to generate compressed waveform data.

Methods and systems for material identification include generating a plurality of first fingerprints for a plurality of material sheets supplied by a supplier at a first step of processing the plurality of material sheets. Each first fingerprint in the plurality of first fingerprints represents a first attenuation measurement of each material sheet in the plurality of material sheets as captured by an array of transducers. Further, the methods and systems include generating a batch mask relating to the first step of processing the plurality of material sheets and based on the plurality of first fingerprints. The batch mask represents a signal correlation of the plurality of first fingerprints that is unique to the plurality of material sheets supplied by the supplier. A target material can be identified using the batch mask.

A signal processing method for ultrasonic inspection includes: a step of generating ultrasonic waves by driving an ultrasonic probe by using a plurality of burst wave signals with different frequencies, respectively, and causing the ultrasonic waves to inject an inspection target; a receiving step of receiving a plurality of multiple reflected waves corresponding to the plurality of burst wave signals having injected the inspection target, respectively; a step of obtaining a plurality of detection signals by executing detection processing of receiving signals of the plurality of multiple reflected waves corresponding to the plurality of burst wave signals, respectively; and a generating step of generating an inspection signal for obtaining an inspection result related to the inspection target by using the plurality of detection signals.