What is shown: The spectrum for the selected analog channel in the current time window. Table rows show harmonic order H, frequency (f_h = h f_1), RMS magnitude, % of fundamental, and phase angle.

How harmonics are computed: Windowed samples are processed with a Hann window, then transformed to frequency bins (FFT/DFT). Reported magnitudes are mapped to integer harmonic orders of the nominal fundamental f_1.

THD formula: THD = sqrt(sum(Vh^2, h=2..Hmax))/V1, where V1 is the fundamental RMS. The panel shows THD as a percentage.

Limits and controls: Max H sets the requested upper harmonic, but results are capped by Nyquist: Hnyq = floor((Fs/2)/f1).

Interpretation notes: Short windows reduce frequency resolution; low or noisy V1 can make THD unstable; only integer harmonics are listed (interharmonics are not separately displayed).