FFT Analyzer Basic FAQ

The term "trigger" originally means "the trigger of a gun or the act of pulling the trigger." In the field of measurement, it refers to a function used in oscilloscopes and other instruments to time the acquisition of a waveform, making a periodic signal waveform appear (apparently) stopped.

In an FFT analyzer, if no trigger is applied (trigger-free), each time data is acquired, problems occur such as [1] periodic waveforms not appearing fixed in the FFT time window, and [2] single signals not being properly captured in the FFT time window. Triggers are used to avoid these problems.

Besides reliably monitoring time waveforms as described above, the main uses of an FFT analyzer include:

• Synchronized summing in time-domain waveforms and Fourier spectra

• Hammering tests such as natural frequency measurement

• Field balancing of rotating bodies

This feature is essential for uses such as those listed above.

	Trigger function (FFT basic terminology glossary)