A method for determining the prestress force of a connection component (10) is proposed. In the method, ultrasonic signals (22) are introduced into the connection component (10) and ultrasonic echoes (24) of the ultrasonic signals (22) are received again. The method comprises the following steps: a) introducing a longitudinal ultrasonic signal and determining a first signal time of flight FTOF.sub.L of the longitudinal ultrasonic signal until the reception of an echo of the longitudinal ultrasonic signal, b) introducing a transverse ultrasonic signal and determining a second signal time of flight FTOF.sub.T of the transverse ultrasonic signal until the reception of an echo of the transverse ultrasonic signal, and c) determining an effective temperature T.sub.eff and the prestress force of the connection component (10) on the basis of the first signal time of flight FTOF.sub.L, the second signal time of flight FTOF.sub.T, previously determined reference data and calibration factors using the assumption that a prestress force F.sub.L ascertained using the first signal time of flight FTOF.sub.L and a prestress force F.sub.T ascertained using the second signal time of flight FTOF.sub.T are equal in magnitude,
wherein steps a) and b) are carried out successively in any desired order or in parallel. A further aspect of the invention relates to a device for carrying out the method.

In some examples, a distributed acoustic detector system may include a frame structure and multiple acoustic detectors. The frame structure may be configured to be retained in a laser-based ophthalmo-logical surgical system aligned to an eye of a patient during therapeutic treatment of the eye of the patient with the laser-based ophthalmological surgical system. The acoustic detectors may be coupled to the frame structure and may be spaced apart from each other and electrically separated from each other.

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.

An ultrasound transmitting and receiving device that can determine whether a contact state between a probe and a bolt is normal without relying on the skill of an operator is provided. The ultrasound transmitting and receiving device includes a probe control unit, an auxiliary storage device, and a contact state determination unit. The probe control unit causes a probe to transmit ultrasound to a bolt, and causes the probe to receive an echo of the transmitted ultrasound. The auxiliary storage device stores one or more pieces of comparison data to be compared with echo data indicating the echo received by the probe. The contact state determination unit compares the echo data with the comparison data, and determines a contact state between the probe and the bolt based on a comparison result.

Disclosed are a linkage device, a transceiver module and a plane stress field measuring device and method capable of achieving synchronous adjustment of distance and angle, and relates to the field of ultrasonic non-destructive testing. The existing technical means for measuring plane stress in the field of ultrasonic testing has the shortcomings that the same testing is only applicable for single materials and the deflection angles of transmitting and receiving transducers are inconsistent. In the application, the linkage device designed by comprising a distance adjusting screw, an angle adjusting screw, a left connecting rod, a right connecting rod, a shaft column and a column lock is adopted, and based on the linkage device, the transceiver module designed by comprising a receiving end wedge, a receiving probe, a transmitting end wedge and a transmitting probe is additionally arranged; based on the transceiver module, the measuring device designed by comprising a pulse transmitting device, an amplifying device and a data acquisition device is additionally arranged, and the stress measuring method applicable for the stress measuring device is provided; and the distance and deflection angle between the receiving probe and the transmitting probe of the detection are adjusted according to a tested part. The application applies to stress measurement in the manufacturing process of mechanical components.

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.

A sonic speed measurement device includes a reception array in which a plurality of reception elements which output reception signals in response to reception of an ultrasonic wave are disposed in one direction, a phase difference detection portion that detects a phase difference between the reception signals output from the reception elements adjacent to each other in a case where the plurality of reception elements receive the ultrasonic wave which propagates in a spherical wave shape from a target point, and a sonic speed calculation portion that calculates a sonic speed of the ultrasonic wave on the basis of the phase difference.

Described are an apparatus, computer program product, and associated methods for shaped waveform acoustic interrogation of substances and materials to determine one or more properties of the materials or substances. In some embodiments, a shaped waveform is formed by summing two or more different waveforms and an acoustic wave is generated according to the shaped waveform. The acoustic wave is transmitted by one or more transmitting transducers through the substance or material and received by one or more receiving transducers. The shaped waveform acoustic wave can have a duration or a period that is less than about 20 μs and can comprise predetermined frequency content. Characteristics of the shaped waveform acoustic wave, as received at the receiving transducer(s), including characteristics such as amplitude, frequency, time of flight, etc., can be associated with said one or more properties of the substance or material to provide for real-time monitoring of these properties.

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.

A system for measuring fluid flow in a wellbore is provided. A probe includes at least a heater. A fiber optic cable is connected to the probe. The system is programmed to perform operations including: changing an output of the heater to thereby change a temperature of drilling fluid moving over a fiber optic cable; measuring a strain on the fiber optic cable caused by changing the temperature of the drilling fluid; preliminarily determining a velocity of the drilling fluid from the measured strain; measuring at least a second parameter of the drilling fluid; adjusting the preliminary determined velocity based on the measured at least a second parameter to yield an adjusted velocity; and determining a flow rate of the drilling fluid based on the adjusted velocity.