Why are the root mean square (RMS) values calculated in LabCart for Windows different from those calculated in LabChart for Mac?

The RMS and Noise Extension for LabChart for Mac v7.2.5 and earlier uses a simple, unweighted averaging window to calculate root mean square (RMS) values while the in LabChart for Windows Arithmetic Channel Calculation RMS function listed below:

rms(source channel, window width in seconds)

uses a weighted, triangular (Bartlett) averaging window.  To recreate the RMS function used by the LabChart for Mac RMS and Noise Extension in LabChart for Windows, enter the following equation into the Arithmetic Channel Calculation of the desired channel:

sqrt(averagesec(source channel^2, window width in seconds))

Note: Current versions of LabChart for Mac and Windows use the same Arithmetic Channel Calculation methods listed above to calculate various RMS values.

 

For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE.