Rockwell Automation 1441-DYN25-MFRF Frequency Response Function Extension Module for the Dynamix 2500 - Manual (Page 23)

Rockwell Automation Publication 1441-UM003A-EN-P - May 2011 23
FRF Frequency Response Function Extension Module Chapter 2
When hitting the object, try to make sure that you have one clean tap and
that the hammer hits directly opposite of where the accelerometer is
located on the object. If this is done correctly, the instrument registers the
hit and increases the number-of-hits count displayed at the bottom of the
screen.
3. Perform all three hammer strikes.
Once complete, a message box appears showing the calculated values for
the applicable settings.
After the automatic parameter setup is complete, you are ready to begin
capturing the FRF data.
The data is collected in the same way as when setting up the automatic
parameters, by hitting the hammer against the object on the side opposite to the
accelerometer.
How many hits you need to take,
based on the Num of Averages
setting in FRF – Setup.