Oscilloscope FFT vs. Spectrum Analyzer

[bittware]

fft analyzer vs oscilloscope

Hello experts,
Could you help me to explain what are the differences between oscilloscope FFT functionality and spectrum analyzer when we tend to carry out conducted disturbance measurement?
Thanks a lot!

 

[Kripton2035]

oscilloscope fft has 8bits depth sometimes 10bits, which makes some 6db sometimes 8db depth.
spectrum analysers go to some 80-100 db depth !!!
that's why they are so expensive...
if the measurement you want needs a big depth you need a spectrum analyser, but if you only consider the first 10db of the spectrum, the oscilloscope fft is enought.

 

[my_books]

**broken link removed**

 

[PaulHolland]

Hi, A spectrum analyzer has a dynamic range of about 100 - 120 dB (strongest compared to weakes signal) A simple osilloscoop FFT analyzer has 50 -60 dB dynamic range. Howeven the more expensive spectrum analyzer also have FFT functionality with much better specifications.

If your looking for a good spectrum analyzer have a look at e-bay !.

Paul.