How do I calculate the root mean square (RMS) of a signal in a LabChart channel?

The software feature that can be used to calculate a signal's RMS in LabChart is the Arithmetic Channel Calculation, which is accessible via the "Channel Setting..." option under the Setup Menu or by left mouse clicking a given channel's title.  Below are the following Arithmetic Channel Calculation equations that can be used to calculate various forms of RMS.

  • rms(source channel, window width in seconds) - calculates the root mean square of the source channel with a triangular (Bartlett) averaging window.
  • sqrt(smoothsec((source channel)^2, window width in seconds)) - alternative form that performs the same calculation as the basic rms() function.
  • sqrt(averagesec((source channel)^2, window width in seconds)) - calculates the root mean square of the source channel with a simple un-weighted (boxcar) averaging window.