EDM Modal Hammer Impact Testing provides the necessary 
features for a single-operator experimental modal test. The 
Hammer Impact GUI features an intuitive step-by-step process, 
allowing a user to easily go through the setup and then the testing. 

The testing process has been designed to help users quickly 
define acquisition parameters, so that more time can be spent on 
analysis. Users can define trigger behavior through the Trigger 
Setup; a Trigger-Preview window allows control over the trigger 
level and pre-trigger delay. For users that may need to review 
their measurements after each acquired frame, the ‘Manual-Arm’ 
trigger mode can be used. When this trigger mode is selected, 
acquired signals will be displayed for review and will prompt the 
user to accept/reject the signal. The auto-arm mode simply auto-
accepts acquired measurements and automatically re-arms the 
trigger, helping to speed up the whole test process. 
Driving Point Selection will help users decide where to place the 
fixed excitation or response reference. The process is to survey 
several candidate driving points and measure their FRFs – this 
allows user to choose the best available DOF for the driving 
point. The FRF at the trial driving-point which best excites most 
of modes can be selected as the driving-point. EDM simplifies the 
data management for this important pre-test survey. 
When taking measurements, the status of the DOFs are indicated 
in a Table window. The status of every measurement point is 
available from this table, which is updated as the test progresses. 
The Trigger Preview window is optimized for viewing experiences 
– featuring a resizable window and adjustable font size. With this 
added flexibility of the trigger window, EDM Modal supports users 
with various display types- users can be far removed from their 
display and still be able to take measurements. 
One common problem associated with hammer testing is 
the “double hit”. EDM Modal Hammer Impact software can 
automatically detect a double hit and give the user the choice to 
automatically or manually reject the double strike.