where <math>R</math> represents the [[Ideal Gas Constant]] (in this case, 8.314 J/(mol·K)), <math>T</math> is the temperature of the gas in [[kelvin]]s, and <math>M</math> is the [[molar mass]] of the gas in kilograms. Note that the unit of mass is in kilograms.
==RMS in frequency domain==
The RMS can be computed also in frequency domain. The [[Parseval's theorem]] is used. For sampled signal:
<math>\sum\limits_{n}{{{x}^{2}}(t)}=\frac{\sum\limits_{n}{{{\left| X(f) \right|}^{2}}}}{n}</math>, where <math>X(f)=FFT\{x(t)\}</math>, <math>n</math> is number of <math>x(t)</math> samples.
In this case, the RMS computed in time domain is the same as in frequency domain:
