Re-scales ODSFRFs to correct for changes in the response levels between multiple Measurement Sets.
This command is only required when ODSFRF measurements are made using multiple Measurement Sets.
If there was any change of response levels between Measurement Sets, it can be observed by overlaying the Reference Auto Spectra from all Measurement Sets, as shown below.
Overlaid Reference Auto Spectra From Multiple Measurement Sets.
The ODSFRFs are re-scaled by first calculating an average Reference Auto Spectrum for all on the Measurement Sets. Then, a scale factor for re-scaling the ODSFRFs in each Measurement Set is calculated using the following formula,
where:
N = Number of Measurement Sets
ARM(i) = Average Magnitude of the Reference Auto spectrum for Measurement Set [ i ]
All ODSFRFs in Measurement Set [ i ] are multiplied by the Scale Factor ( i ).
If the Line cursor is displayed, ARM(i) is calculated at the Line cursor position
If the Band or Peak cursor is displayed, ARM(i) is calculated using all the samples in the band
If no cursors are displayed, ARM(i) is calculated using all samples of each Reference Auto spectrum