THD Measurement with an Oscilloscope and FFT - Easily Calculate the Distortion Factor

Total Harmonic Distortion, or THD for short, is an important measure of the harmonic content of signals in power supply networks and electronic assemblies, such as audio amplifiers. Usually, special measurement devices are necessary for determining the THD. However, if you have a digital oscilloscope with FFT functionality, you can calculate the THD with a little mathematics.