The code presented here concerns the processing of data stored in the Data Storage Object (DSO file) obtained from the Velleman PCSGU250 measurement complex.
The main purpose is to calculate the Noise Power Spectral Density (Noise PSD) and Noise Voltage referred to the output of the two or four terminal circuit using А–weighting filter.
The code is based on the theory described in:
 A. Kay, Operational Amplifier Noise: Techniques and Tips for Analyzing and Reducing Noise (Chapter 5). Oxford, Newnes, 2012.
 D. Manolakis, V. Ingle. Applied Digital Signal Processing (Chapter 14). Cambridge, Cambridge University Press, 2011.
 Design Response of Weighting Networks for Acoustical Measurements ANSI S1.42-2001. Washington, American National Standards Institute, 2001.