Root Mean Square (rms)

This is the square root of sum of squares of individual observations divided by the total number of observations made.

The r.m.s. value of a function, x(t), over a time interval between t₁ and t₂ is specified by the following formula:

Because energy varies as the square of amplitude, rms tracks the amount of energy in a complex signal. In noise data, the rms value should be approximately the same as the standard deviation.

See also: Crest Factor.