The FFT application module adds FFT (Fast Fourier Transform) measurement capabilities to your oscilloscope. The FFT process mathematically converts the standard time-domain signal (repetitive or single-shot acquisition) into its frequency components, providing spectrum analysis capabilities.
Being able to quickly look at a signal’s frequency components and spectrum shape is a powerful research and analysis tool. FFT is an excellent troubleshooting aid for:

• Testing impulse response of filters and systems
• Measuring harmonic content and distortion in systems
• Identifying and locating noise and interference sources
• Analyzing vibration
• Analyzing harmonics in 50 and 60 Hz power lines