A device and a method for determining and/or monitoring at least one process variable of a medium include a sensor unit having a mechanically oscillatable unit, at least a first piezoelectric element, a temperature detection unit for determining and/or monitoring a temperature of the medium and an electronics unit. The device is embodied to excite the mechanically oscillatable unit by means of an excitation signal such that mechanical oscillations are executed, to receive mechanical oscillations of the oscillatable unit and convert them into a first received signal, to transmit a transmitted signal and to receive a second received signal. The electronics unit is embodied, based on the first and/or second received signal, to determine the at least one process variable and, based on a third received signal received from the temperature detection unit, to determine the temperature of the medium.

A device and a method for determining and/or monitoring at least one process variable of a medium include a sensor unit having a mechanically oscillatable unit, at least a first piezoelectric element, a temperature detection unit for determining and/or monitoring a temperature of the medium and an electronics unit. The device is embodied to excite the mechanically oscillatable unit by means of an excitation signal such that mechanical oscillations are executed, to receive mechanical oscillations of the oscillatable unit and convert them into a first received signal, to transmit a transmitted signal and to receive a second received signal. The electronics unit is embodied, based on the first and/or second received signal, to determine the at least one process variable and, based on a third received signal received from the temperature detection unit, to determine the temperature of the medium.

Methods, apparatus, and articles of manufacture are disclosed. An example pre-amplifier includes a demodulator to generate an oscillating signal having a measurement center frequency, combine an acoustic emission signal and the oscillating signal to generate a sideband acoustic emission signal, sample spectral data of the sideband acoustic emission signal at an intermediate center frequency in an intermediate frequency bandwidth, and generate demodulated acoustic emission data based on a mapping of the sampled spectral data to the measurement center frequency, the measurement center frequency different from the intermediate center frequency, and a transmitter to transmit the demodulated acoustic emission data to a computing device.

Methods, apparatus, and articles of manufacture are disclosed. An example pre-amplifier includes a demodulator to generate an oscillating signal having a measurement center frequency, combine an acoustic emission signal and the oscillating signal to generate a sideband acoustic emission signal, sample spectral data of the sideband acoustic emission signal at an intermediate center frequency in an intermediate frequency bandwidth, and generate demodulated acoustic emission data based on a mapping of the sampled spectral data to the measurement center frequency, the measurement center frequency different from the intermediate center frequency, and a transmitter to transmit the demodulated acoustic emission data to a computing device.

A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (F.sub.max) and the number of lines of resolution (N.sub.lines) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.

A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (F.sub.max) and the number of lines of resolution (N.sub.lines) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.

A non-transitory computer-readable storage medium storing a program that causes a computer to execute a process, the process includes acquiring first sound data collected by a first microphone and second sound data collected by a second microphone during traveling of a vehicle in which the first microphone is provided in vicinity of a front wheel and the second microphone is provided in vicinity of a rear wheel; and detecting a cavity under a road surface where the vehicle has traveled based on a difference between the acquired first sound data and the acquired second sound data.

A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (F.sub.max) and the number of lines of resolution (N.sub.lines) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.

A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (F.sub.max) and the number of lines of resolution (N.sub.lines) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.

A system for monitoring and identifying states of a semiconductor device, the system including at least one acoustic sensor for sensing acoustic emission emitted by at least one semiconductor device operating at a voltage of less than or equal to 220 V, the at least one acoustic sensor outputting at least one acoustic emission signal and a signal processing unit for receiving the at least one acoustic emission signal from the at least one acoustic sensor and for analyzing the at least one acoustic emission signal, the signal processing unit providing an output based on the analyzing, the output being indicative at least of whether the at least one semiconductor device is in an abnormal operating state with respect to a normal operating state of the semiconductor device.