Noise generator

(white, bandpass, pink and determinate noise)

The Software Signal generator allows to produce flat, band, pink and defined noise at the DAC output.

The program Signal generator allows to produce noise signals (white, bandpass, pink, determinate noise) at the DAC output of the connected devices.

The noise type to be generated is to be selected from the context menu: right-click the section with the noise name and select the noise type you need.
Signal Generator - selecting signal type - White signal

White noise

White noise is a noise of stationary type and its spectral components are evenly distributed along the frequency range.

Signal generator - main program window with the set parametersMain program window specifying the signal parameters

Multichannel oscilloscope - the diagram of generated noiseOscilloscope pattern of the generated noise

Narrow-band spectrum- generator 1- White noise spectrum

White noise signal spectrum

White noise spectrum in the program Spectral analysis of the octave band - Generator 1White noise signal spectrum: share-octave analysis

In the “White noise” and “Bandpass noise” modes, the “Noise” tab of the program “Signal generator”  has an additional section “Kurtosis” (the term is also sometimes referred to as excess kurtosis).

The kurtosis is a factor that reflects the peakedness and the “tailedness” of the distribution. The kurtosis is based on the fourth moment of the distribution (μ4). In the case of normal distribution, the kurtosis value is 3.

The deviation of distribution for the white noise signal spectrum from a normal distribution with kurtosis ratio = 3 is less than 10%.

White noise signal histogram - Kurtosis 3Histogram of White noise signal

Signal generator - White noise - Kurtosis 6
White noise signal generator: excess kurtosis – 3 (kurtosis – 6)

The possibility of setting the excess kurtosis value of the noise signal also allows to control the distribution probability, thus, it is possible to make laboratory testing quite similar to real impacts, to which the specimen is exposed in the course of its operation.

As you can clearly see from the oscilloscope pattern of the signal, the higher is the excess kurtosis level, the more high-power noise peaks (pulses) there are in the noise signal. The histogram also clearly outlines the changes in the distribution pattern – the peakedness and “tailedness” become more apparent than in the case of the normal distribution. These changes make it clear that as the excess kurtosis (kurtosis) value increases, the distribution shifts to the average distribution pattern and has a lower standard deviation value than in the case of the normal distribution.

Multichannel oscilloscope - White noise signal - Kurtosis 6 White noise signal oscilloscope pattern: excess kurtosis – 3 (kurtosis – 6)

Histogram - Generator 1 - White noise signal - Kurtosis 6

Histogram of White noise signal: excess kurtosis – 3 (kurtosis – 6).

Nowadays increasing of the excess kurtosis ratio is a popular method of accelerating the broad-band random vibration impact testing, since the increase of kurtosis ratio also leads to the growth of the acceleration peak level, while acceleration RMS value remains unchanged.

The Software Signal generator is included into the scope of the following  Software packages:

Signal  generator is included into Generators program section.