A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

A method for operating a machine plant having a shaft train, including: a) determining the harmonic frequency of a torsional vibration mode of the shaft train and determining mechanical stresses arising during a vibration period of the torsional vibration mode; b) determining a correlation for each torsional vibration mode between a first stress amplitude, at a position of the shaft train that carries risk of stress damage, and a second stress amplitude, at a measurement location of the shaft train, using stresses determined for the respective torsional vibration mode; c) establishing a maximum first stress amplitude for the position; d) establishing a maximum second stress amplitude, corresponding to the maximum first stress amplitude, for the measurement location; e) measuring the stress of the shaft train while rotating; f) determining a stress amplitude at each harmonic frequency; g) emitting a signal when the stress amplitude reaches the maximum second stress amplitude.

A method for operating a machine plant having a shaft train, including: a) determining the harmonic frequency of a torsional vibration mode of the shaft train and determining mechanical stresses arising during a vibration period of the torsional vibration mode; b) determining a correlation for each torsional vibration mode between a first stress amplitude, at a position of the shaft train that carries risk of stress damage, and a second stress amplitude, at a measurement location of the shaft train, using stresses determined for the respective torsional vibration mode; c) establishing a maximum first stress amplitude for the position; d) establishing a maximum second stress amplitude, corresponding to the maximum first stress amplitude, for the measurement location; e) measuring the stress of the shaft train while rotating; f) determining a stress amplitude at each harmonic frequency; g) emitting a signal when the stress amplitude reaches the maximum second stress amplitude.

The present disclosure provides a method for detecting a bandwidth of a linear vibration motor, including a linear vibration motor which comprises a housing and a motor vibrator. The method includes the following steps: step S1: setting a target displacement level of the linear vibration motor; step S2: measuring a displacement frequency response curve of the motor vibrator with reference to the target displacement level; step S3: comparing the displacement frequency response curve obtained in step S2 with a preset standard target displacement frequency response curve, determining whether the displacement frequency response curve is qualified, and if it is qualified, entering step S4; step S4: measuring a bandwidth of the linear vibration motor.

The invention relates to a system for representing vibrations for a vehicle, comprising a vehicle seat with an upper part and a lower part, which are mounted movably relative to each other by means of a vibration device, wherein at least a first sensor, which is adapted to detect at least one first characteristic of a first acceleration of the upper part relative to the lower part, is arranged on the upper part, and wherein at least one second sensor, which is adapted to detect at least one second characteristic of a second acceleration of the lower part relative to a subsurface of the vehicle, is arranged on the lower part, wherein a display device is arranged with a first section and a second section, in each case exhibiting a complete division into at least two, preferably three segments, wherein the size ratios of the at least two segments to one another can be updated depending on a current value of the at least one first characteristic or the at least one second characteristic.

The invention relates to a system for representing vibrations for a vehicle, comprising a vehicle seat with an upper part and a lower part, which are mounted movably relative to each other by means of a vibration device, wherein at least a first sensor, which is adapted to detect at least one first characteristic of a first acceleration of the upper part relative to the lower part, is arranged on the upper part, and wherein at least one second sensor, which is adapted to detect at least one second characteristic of a second acceleration of the lower part relative to a subsurface of the vehicle, is arranged on the lower part, wherein a display device is arranged with a first section and a second section, in each case exhibiting a complete division into at least two, preferably three segments, wherein the size ratios of the at least two segments to one another can be updated depending on a current value of the at least one first characteristic or the at least one second characteristic.

Methods, apparatuses, and systems for analysing the state of power transformers are described. A method may include providing at least one sensor arranged relative to a power transformer, retrieving at least one vibroacoustic signal from said at least one sensor, performing a time-frequency decomposition of said at least one vibroacoustic signal from a time domain to a frequency domain, identifying one or more vibroacoustic harmonic frequencies provided by the fast Fourier transformation of the at least one vibroacoustic signal, calculating an amplitude value and a phase angle related to the one or more harmonic frequencies, retrieving an electromagnetic signal emitted from the power transformer, a temperature generated by the power transformer, or both, and providing at least one analysed information from the amplitude value and the phase angle related to the one or more harmonic frequencies, the electromagnetic signal, the temperature, or any combination thereof.

Methods, apparatuses, and systems for analysing the state of power transformers are described. A method may include providing at least one sensor arranged relative to a power transformer, retrieving at least one vibroacoustic signal from said at least one sensor, performing a time-frequency decomposition of said at least one vibroacoustic signal from a time domain to a frequency domain, identifying one or more vibroacoustic harmonic frequencies provided by the fast Fourier transformation of the at least one vibroacoustic signal, calculating an amplitude value and a phase angle related to the one or more harmonic frequencies, retrieving an electromagnetic signal emitted from the power transformer, a temperature generated by the power transformer, or both, and providing at least one analysed information from the amplitude value and the phase angle related to the one or more harmonic frequencies, the electromagnetic signal, the temperature, or any combination thereof.

A system and method for detecting passage of a pipeline pig, the system and method including a passive impulse detector [10] having a housing [13]; a non-intrusive connection [15] of the housing to an exterior wall [17] of a pipeline [P], at least one vibration sensor [11] housed by the housing; and signal processing [23] including at least one band pass filter [27] configured to receive data collected by the vibration sensor, the vibration sensor and band pass filter configured to monitor frequencies in a predetermined range indicating the impulse. The selected frequencies should be those more easily detectable above the baseline (signature or natural resonance) frequency of the section of pipeline being monitored. In some embodiments, the selected frequencies are lower frequencies. No portion of the passive pipeline pig signal intrudes into an interior of the pipeline.