A bio-signal acquiring apparatus includes a sensor part and a signal processor. The sensor part includes a bio-signal sensor, a load sensor, and an ultrasonic sensor array, the bio-signal sensor configured to detect a bio-signal of an object that comes into contact with the sensor part, the load sensor configured to detect a contact load of the object, and the ultrasonic sensor array configured to detect contact load distribution of the object. The signal processor is configured to obtain a contact load of the object at a region of interest based on the contact load and the contact load distribution, and configured to output the contact load of the object at the region of interest and the bio-signal.

A system for mapping data of force transmission from a plurality of force-imparting points to each force-measuring device is disclosed. A linear actuator assembly includes a Z-axis actuator and a slider. A load cell is secured to the slider, such that actuation of the Z-axis actuator is mechanically coupled to a vertical movement of the load cell via the slider. A sample stage includes a sample stage positioner and is configured to retain a sample including at least one force-measuring device. The load cell is configured to impart a time-varying applied force to the sample. The controller is configured to control actuation of the sample positioner to position the load cell at each one of a plurality of force-imparting points on the sample and, for each respective force-imparting point, control the actuation of the Z-axis actuator. A computer is configured to generate a map of data of force transmission from the plurality of force-imparting points to the force-measuring device in accordance with digital transducer data obtained from the force-measuring device upon the imparting of the time-varying applied force at each force-imparting point.

A force-measuring device testing system is disclosed. A linear actuator assembly includes a Z-axis actuator and a slider. A load cell is secured to the slider, such that actuation of the Z-axis actuator is mechanically coupled to a vertical movement of the load cell via the slider. The load cell is configured to impart a time-varying applied force to the sample which includes a force-measuring device. A load cell signal processing circuitry is configured to measure force signals at the load cell and output amplified force signals to the controller. The controller is configured to repeatedly carry out the following until a desired force trajectory has been executed: (1) calculate digital force signals in accordance with the amplified force signals, (2) calculate a next actuation of the Z-axis actuator in accordance with a desired force trajectory and an elastic parameter, and (3) control the actuation of the Z-axis actuator in accordance with its next calculated actuation.

A method and device for determining tensile force and adhesive force during the unwinding of a film from a roll without affecting the film, and which are usable at any radius of the spool and at any unwinding speed. The method and the device are based on determining the point where the film releases from the spool, and make use of the reflection of an ultrasonic wave. Emitted and reflected waves are radial at least when the emitted wave is incident upon the film which has not released from the spool. The method and device find applicability where tensile force, caused by the resistance of the roll to rotation, and also by adhesion of the film to the roll, must be determined. The method and device also find applicability where the adhesive force of the film to the roll must be determined.

An improved ultrasonic transducer for measuring stretch loads on bolts is provided. The improved ultrasonic transducer is separated into a pickup unit and a base sensor unit. The base sensor unit includes a piezo ceramic inside an aluminum can covered by a PCB for protection, which is surrounded by a strong magnet. Honey is used as a couplant between the base sensor unit and the bolt during operation. The base sensor unit stays on the bolt before and after tightening without changing the mechanical bonding between the sensor and bolt therefore achieving higher accuracy stretch readings. The base sensor unit is low cost and reusable, as it can be placed on number of bolts before tightening and can be removed after tightening, washed and then reused.

Disclosed is a method for determining internal uniaxial stress of steel members based on transverse wave phase spectrum, including: manufacturing a replicated steel member of an in-service steel structure member, where the replicated steel member and the in-service steel structure member are the same in material and thickness; loading a test on the replicated steel member to obtain two stress-spectral parameters; performing ultrasonic determination on the in-service steel structure member using an ultrasonic determination device; and collecting transverse wave signals using a signal acquisition system; processing the collected transverse wave signals through an information processing device to obtain a derived curve of the phase spectrum; capturing a first response frequency of the phase spectrum from the phase spectrum derived curve; and obtaining a uniaxial stress of the in-service steel structure member according to the stress-spectral parameters.

The present disclosure relates to the technical field of non-destructive detecting of residual stress, and in particular to a non-destructive detecting device for component residual stress gradient. the non-destructive detecting device comprises: groups of transmitting transducers and receiving transducers arranged symmetrically to each other, the transmitting transducers closer to the symmetry axis have greater excitation frequencies; an acoustic wedge coupled to the groups of transmitting transducers and receiving transducers, wherein groups of cylindrical transmitting tunnels and receiving tunnels are provided obliquely within the transmitting connection area and the receiving connection area through their top surfaces and toward their bottom surfaces, the transmitting transducers are coupled to the transmitting tunnels in a one-to-one correspondence, the receiving transducers are coupled to the receiving tunnels in a one-to-one correspondence, and the bottom surfaces of the transmitting connection area and the receiving connection area are pressed against the surface of the detected component; and a calculation processing module electrically connected to the transmitting transducers and the receiving transducers. The non-destructive detecting device solves the problem that the residual stress values of components at different penetration depths cannot be detected at the same time.

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

An improved ultrasonic transducer for measuring stretch loads on bolts is provided. The improved ultrasonic transducer is separated into a pickup unit and a base sensor unit. The base sensor unit includes a piezo ceramic inside an aluminum can covered by a PCB for protection, which is surrounded by a strong magnet. Honey is used as a couplant between the base sensor unit and the bolt during operation. The base sensor unit stays on the bolt before and after tightening without changing the mechanical bonding between the sensor and bolt therefore achieving higher accuracy stretch readings. The base sensor unit is low cost and reusable, as it can be placed on number of bolts before tightening and can be removed after tightening, washed and then reused.

An ultrasonic testing device and method for the connection force of interference fit. The motion control module can realize accurate positioning for the interference fit part and accurate control for motion in the circumferential direction and the axial direction; scanning increments of the circumferential direction and the axial direction are set, and the motion control module drives the interference fit part to perform circumferential and axial point scanning until the testing of the whole matching surface is completed. The ultrasonic signal measured by the point focusing water immersion probe is transmitted to a PC through a control loop in the testing process. Then the stress distribution of the matching surface is obtained through the relationship between the ultrasonic signal and contact stress Finally, the size of the connection force is calculated according to the static friction coefficient.