what is rms
(March 2010). The root mean square (abbreviated RMS or rms), also known as the quadratic mean, in statistics is a statistical measure defined as the square root of the mean of the squares of a sample.n the case of a set of n values, the RMS. The corresponding formula for a continuous function (or waveform) f(t) defined over the interval is. and the RMS for a function over all time is. The RMS over all time of a periodic function is equal to the RMS of one period of the function.