A frequency measurement method is provided, which comprising: sampling a voltage to be measured with a fixed sampling frequency; obtaining a positive-sequence voltage angle change amount for a predetermined operation interval time by using a sampling sample obtained by the sampling and based on a discrete Fourier transform (DFT) calculation; obtaining a frequency offset amount by using the positive-sequence voltage angle change amount; and obtaining a frequency-related measurement value by using the frequency offset amount. A frequency measurement apparatus is also provided. measurement value. This frequency measurement method does not require iterative calculations, and directly obtains frequency-dependent measurement values, thereby responding quickly to frequency changes. In addition, a frequency measurement apparatus is also provided.

A method of signal processing includes receiving samples of a signal and processing the samples using a time-windowed transform function to generate spectral data corresponding to each time window. The method includes generating first spectrogram data based on magnitudes of the spectral data and generating second spectrogram data based on phase differences of the spectral data. The method further includes combining the first spectrogram data and the second spectrogram data to generate a combined spectrogram and processing the combined spectrogram to generate output.

A method of signal processing includes receiving samples of a signal and processing the samples using a time-windowed transform function to generate spectral data corresponding to each time window. The method includes generating first spectrogram data based on magnitudes of the spectral data and generating second spectrogram data based on phase differences of the spectral data. The method further includes combining the first spectrogram data and the second spectrogram data to generate a combined spectrogram and processing the combined spectrogram to generate output.

A method for detecting a direct current component in an inductive device, for example in a transformer or choke, includes using a computer for recording an oscillation signal, either of sound emitted from the device or of mechanical oscillation of the device, determining the frequency range of the oscillation signal, determining the value of at least one odd frequency in the frequency range, comparing the value of the odd frequency with the value of at least one even frequency in the frequency range, and determining a direct current component when the value of the odd frequency differs from the even frequency by a predefined amount. The method can be carried out without measuring equipment in the interior of an inductive device and without the involvement of an expert. A computer program product for carrying out the method is also provided.

A method for detecting a direct current component in an inductive device, for example in a transformer or choke, includes using a computer for recording an oscillation signal, either of sound emitted from the device or of mechanical oscillation of the device, determining the frequency range of the oscillation signal, determining the value of at least one odd frequency in the frequency range, comparing the value of the odd frequency with the value of at least one even frequency in the frequency range, and determining a direct current component when the value of the odd frequency differs from the even frequency by a predefined amount. The method can be carried out without measuring equipment in the interior of an inductive device and without the involvement of an expert. A computer program product for carrying out the method is also provided.

An optical device includes a low-noise illumination source, a support device, an ultra low-noise detector, an analog-to-digital converter, and a controller. The low-noise illumination source is configured to generate a single beam of radiation. The support device is configured to support an object and to pass the single beam of radiation through the object. The object directly blocks, absorbs, or deflects portions of the single beam of radiation, thereby directly modulating the single beam of radiation. The low-noise detector is configured to detect the modulated single beam of radiation and to output an analog signal representative of vibrational spectra of the object. The modulated single beam of radiation is non-interferometric. The analog-to-digital converter is configured to convert the detected analog signal into a digital signal. The controller is configured to analyze and generate vibrational spectra of the object from the digital signal represented as a range of events over time.

An optical device includes a low-noise illumination source, a support device, an ultra low-noise detector, an analog-to-digital converter, and a controller. The low-noise illumination source is configured to generate a single beam of radiation. The support device is configured to support an object and to pass the single beam of radiation through the object. The object directly blocks, absorbs, or deflects portions of the single beam of radiation, thereby directly modulating the single beam of radiation. The low-noise detector is configured to detect the modulated single beam of radiation and to output an analog signal representative of vibrational spectra of the object. The modulated single beam of radiation is non-interferometric. The analog-to-digital converter is configured to convert the detected analog signal into a digital signal. The controller is configured to analyze and generate vibrational spectra of the object from the digital signal represented as a range of events over time.

The present invention concerns a method for processing radar signals in a detection system comprising at least one computing architecture comprising at least one memory to store at least one set of signal-related programs and/or data, at least one processor executing said programs to implement said method comprising at least a first step (E1) to digitize radar signals, a second step to generate spectra from the digitized signals obtained at the first step (E1), via FFT computation, said method being characterized in that FFT computation at the spectra generation step (E2) comprises at least one multi-FFT processing comprising at least: simultaneous FFT computation (E20) of different sizes with automatic selection of said sizes and real-time selection of signals (E21) in all the spectra of the different FFT computations, via a selection algorithm.

The present invention concerns a method for processing radar signals in a detection system comprising at least one computing architecture comprising at least one memory to store at least one set of signal-related programs and/or data, at least one processor executing said programs to implement said method comprising at least a first step (E1) to digitize radar signals, a second step to generate spectra from the digitized signals obtained at the first step (E1), via FFT computation, said method being characterized in that FFT computation at the spectra generation step (E2) comprises at least one multi-FFT processing comprising at least: simultaneous FFT computation (E20) of different sizes with automatic selection of said sizes and real-time selection of signals (E21) in all the spectra of the different FFT computations, via a selection algorithm.

The present invention relates to a test or measurement instrument, comprising a test unit, a memory, a display, a network interface and a processing unit. The processing unit is configured to generate a machine-readable representation of data such as a QR code which comprises encoded address information of the data file stored in the memory. The processing unit is further configured to display the generated QR code on the display for enabling an external network device to download the stored data file via the network interface after having scanned the displayed QR code and decoded the address information encoded therein. The invention further relates to a method for enabling a network device to downloaded data stored in a test or measurement instrument.