A method and apparatus of condition monitoring and detection of vibration generated from at least two different sources using a single sensor/transducer is provided. The method and apparatus provides switchably adapting signal processing, such as amplification and frequency filtering, to one at a time of the at least two different signal sources. An example of which is vibration sources. This adapts the analogue signal from the sensor/transducer to the analogue to digital converter and any further optional analogue signal processing, so that it is possible to maximize use of available dynamic range of these and without any saturation of these. Suitably, the signal processing to analyze the vibration signals is also appropriately adapted to the vibration source in question.

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.

A method for measuring the applied load on a towing hook/or a tow bar accessory of a towing hook arrangement for a vehicle, and a towing hook arrangement for a vehicle. The towing hook arrangement comprises a towing hook and/or a tow bar accessory arranged on a tow bar, the towing hook arrangement also comprises a sensor arrangement having at least one actuator and at least one sensor, the sensor arrangement is adapted to detect an imparted vibration on the tow bar and use the detected imparted vibration to determine the applied load on the towing hook and/or the tow bar accessory.

The invention relates to a system for the in-line measurement of mill liner wear and mill bolt tension, which includes: an acoustic-wave emitter, an acoustic-wave receiver, an electronic circuit, an energy source and a communication device, all at the threaded end of a certain number of bolts; a device in the vicinity of the mill for administering communication and gathering data; and a system in a remote position for processing and displaying data.

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.

A system, probe and method accurately measure the strain or extension of a fastener that occurs as a nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal and shear wave reflections, which result in a higher magnitude and more easily and precisely measurable reflected signal peak than a signal peak associated with a signal directly reflected against the opposite end of the fastener.

A method for estimating the state of wear of a plain bearing comprises: establishing a time profile of at least one friction event from a structure borne noise signal by a mathematical friction event model, determination of a measure, which characterizes at least one friction event based on a time duration of the at least one friction event, the amplitude of the at least one friction event and/or an integral measure over the at least one friction event, combination of the measure, accumulated over time, with an angle indication for the at least one friction event at the circumference of the plain bearing in order to determine a spatially resolved wear model of the plain bearing, wherein the spatially resolved wear model is obtained by an estimating filter, and outputting a signal in accordance with the wear model to characterize the state of wear.

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 rock breaking device and a method of monitoring a condition of a tool of a rock breaking device is provided. The rock breaking device includes a frame, a tool, a device for generating stress waves in the tool, measuring means for measuring the stress wave propagating in the tool and at least one computing unit for monitoring a condition of the tool on the basis of the measured stress wave. The at least one computing unit is configured to determine a condition of the tool on the basis of a time of propagation of at least one reflected stress wave component of the stress wave and at least one additional property of the same reflected stress wave component.

An acoustic disdrometer is provided for measuring precipitation. The acoustic disdrometer has an acoustic transducer positioned within an acoustic chamber defined by an acoustic shell. Precipitation impacting the acoustic shell generates sound waves that are collected by the acoustic transducer for processing.