The invention relates to a method for determining the root mean square value of a vibration variable that is measured on a machine. A test measurement is carried out in order to obtain a test signal of the vibration variable with a test signal length; the influence of shortening the signal length of the test signal on the associated root mean square value is estimated and the relative deviation of the root mean square value emerging for a shortened signal length from the root mean square value emerging for the full test signal length is estimated therefrom as a function of the signal length to obtain a root mean square value error function; and a measurement of the vibration variable is carried out for determining the root mean square value. The measurement duration of this measurement is selected on the basis of the root mean square value error function.

A display control device includes a control unit that displays a sound pressure level distribution of predetermined sound data and a recordable range corresponding to a quantization bit depth during recording of the sound data on a display unit.

A method for estimating the sensitivity in an environment of a sound emission detector device capable of detecting a physical phenomenon producing a spatially limited sound emission, said detector device comprising a transducer array, said method comprising a) receiving at least one signal from at least one respective transducer of the transducer array, said array being place within said environment, b) estimating from the at least one signal received at step a) a detection threshold value of a spatially limited source sound emission parameter, c) estimating from the detection threshold value estimated at step b) a quantity representative of a magnitude of the physical phenomenon, d) displaying the quantity estimated at step c) so as to inform the user of the sensitivity of the detector.

A system and related method for precisely monitoring fluid or gas flows, comprising: a flow meter comprising a mechanical metering component; the mechanical metering component comprising a ferrous material; a three-axis magnetic field sensor for sensing fluctuations of a magnetic field arising from movements of the ferrous material, and specifically, for sensing a magnetic field vector of the magnetic field; computer processing for receiving data from the magnetic field sensor and storing magnetic field behavior data representing time behavior of the magnetic field vector in three space dimensions; calibration programming for analyzing and learning a magnetic signature of the meter; programming for storing a unique calibration pattern of the magnetic signature representing baseline behaviors thereof; and comparison programming for comparing behaviors of the magnetic field during operation with the calibrated baseline behaviors and thereby deducing flows which are occurring during operation as a function of time under various conditions.

A hydrophone used for measuring acoustic energy from a high frequency ultrasound transducer, or a method of manufacturing the membrane hydrophone. The membrane assembly is supported by the frame and comprises a piezoelectric. The hydrophone also includes an electrode pattern formed within the piezoelectric to define an active area. In addition, the hydrophone includes a built in-situ coaxial layer connected to the active area.

An electronic device includes a processor, and a memory containing instructions that, when executed by the processor, cause the electronic device to learn a sound emitted by a legacy device and to issue an output when the electronic device subsequently hears the sound. For example, the electronic device can receive a training input and extract a compact representation of a sound in the training input, which the device stores. The device can receive an audio signal corresponding to an observed acoustic scene and extract a representation of the observed acoustic scene from the audio signal. The electronic device can determine whether the sound is present in the observed acoustic scene at least in part from a comparison of the representation of the observed acoustic scene with the representation of the sound. The electronic device emits a selected output responsive to determining that the sound is present in the acoustic scene.

A method and system is disclosed for determining an optimum drive signal for an acoustic transducer. A pulse signal is employed as a wideband reference signal V.sub.r(t); and, in a pulse-echo measurement a corresponding wideband echo signal V.sub.e(t) is obtained. A normalized loop frequency response {circumflex over (X)}(f) for the acoustic transducer is defined as a ratio of a Fourier Transform of the V.sub.e(t) to a Fourier Transform of the V.sub.r(t), and a normalized loop time response X(t) is defined as an Inverse Fourier Transform of the {circumflex over (X)}(f). An optimum drive signal B(t) for the acoustic transducer is defined as B(t)*G(t), wherein a coefficient is determined to multiply a function G(t), in which the function G(t) is derived from one of the normalized loop time response X(t) and the normalized loop frequency response {circumflex over (X)}(f).

The present invention is a pressure coupling chamber (1) developed for comparison calibrations of acoustic pressure-sensitive hydrophone (2) in the frequency range from Hz to 1 kHz. A hydrophone (2), reference receiver unit (3) and acoustic source (6) under test are acoustically coupled in the chamber through the air-filled medium inside the pressure coupling chamber (1). Acoustic sources (6) that are going to create acoustic pressure in the pressure coupling chamber (1), placed on the side walls of the chamber (1) to surround the pressure-sensitive active surface of hydrophone (2), are driven to create a hydrostatic pressure effect in the related frequency range in the chamber. Calibration of tested hydrophone (2) with comparison method is carried out by measuring the output voltages of tested hydrophone (2) and the reference receiver unit (3).

A vibration rectification error correction circuit includes a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

There is disclosed a method of detecting failures or anomalies of a large number of sensor terminals without using manpower or expensive equipment in the seismic exploration business. The method includes preparing a plurality of sensor terminals having sensors that detect vibrations from outside, the plurality of sensor terminals receiving the vibrations and outputting vibration reception signals, and comparing a first vibration reception signal output by a first sensor terminal with a second vibration reception signal output by a second sensor terminal, thereby detecting if one of the first sensor and the second sensor is failed or anomalous.