What is the FFT (Fast Fourier Transform) math function of an oscilloscope useful for?

What is the FFT (Fast Fourier Transform) math function of an oscilloscope useful for?

There are a variety of uses that can benefit from viewing the frequency spectrum of a signal. Using the FFT math function on a time domain signal provides the user with frequency domain information and can provide the user a different view of the signal quality, resulting in improved measurement productivity when troubleshooting a device-under-test. Examples include:

• Analyze harmonics in power lines
• Measure harmonic content and distortion in systems
• Characterize noise in DC power supplies
• Test impulse response of filters and systems
• Analyze vibration

More information and examples can be found in the application note titled FFT Applications for TDS Oscilloscopes.