Time Waveform Measurements

In order to display ODS's or mode shapes from a set of response time waveform measurements, they must all be acquired so that each measurement contains the response of the structure at the same moment in time. Another way of saying this is that all structural responses must contain the correct magnitude & phase relative to one another for each time sample

Simultaneous acquisition requires a separate sensor for each point & direction (DOF) of measurement, and a large, multi-channel data acquisition system. Since this is typically too expensive, data is usually acquired a few channels at a time in separate Measurement Sets.

Repeatable Acquisition

Acquisition of a Repeatable Event.