92 Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide
4 FFT Spectral Analysis
You can make peak-to-peak, maximum, minimum, and average dB
measurements on the FFT waveform. You can also find the frequency value at
the first occurrence of the waveform maximum by using the X at Max Y
measurement.
To adjust the FFT waveform scale and offset
1 Make sure the multiplexed scale and position knobs above and below the [FFT]
key are selected for the FFT waveform.
If the arrow to the left of the [FFT] key is not illuminated, press the key.
2 Use the multiplexed scale and position knobs next to the [Math] key to re-size
and re-position the math waveform.
The following FFT spectrum was obtained by connecting a 2.5 V, 100 kHz square
wave to channel 4. Set the horizontal scale to 50 µs/div, vertical sensitivity to
1 V/div, Units/div to 20 dBV, Offset to -40.0 dBV, Center frequency to 500 kHz,
frequency Span to 1 MHz, and window to Hanning.
See Also • “Searching for FFT Peaks" on page 93
• “FFT Measurement Hints" on page 93
• “FFT Units" on page 95
• “FFT DC Value" on page 95
To Next Page
Loading...
