Page 125 - Master Handbook of Acoustics
P. 125
FIGURE 5-18 A distorted periodic wave is measured with a constant-bandwidth analyzer. The
fundamental f is set for some reference voltage, taken here as 1.00 V. Using a wave analyzer, the
0
amplitude of the second harmonic at 2f is measured as 0.10 V. The wave analyzer similarly yields
0
the amplitudes of each harmonic as shown. The root-mean-square (RMS) of the harmonic voltages is
then compared to the 1.00-V fundamental to find the total harmonic distortion (THD) expressed in
percentage.
