Distortion is the addition of signal components that are not part of the original signal. These additional components can be found at harmonics and intermodulations of the input frequencies. Distortion is generally an unwanted response because of non-linearities in the device under test.
Distortion measurements use the following equations:
F is the fundamental tone root mean square (RMS) level
K is the maximum harmonic in the measurement bandwidth
Hi is the ith harmonic RMS level, where i is an integer <2..K>
N is the noise RMS level
Use the Distortion VIs to perform distortion measurements.
Use the Tone Measurements Express VI to develop and interactively configure distortion and channel evaluation measurements.