CF-5200 Frequently Asked Questions

This is a power spectral density (abbreviated as PSD) display function.

When analyzing data resembling random signals, the resolution changes depending on the frequency range, so changing the frequency range alters the Y-axis values.

When displayed as power spectrum (i.e., power spectral density) per 1 Hz, the difference in resolution improves and becomes smaller.

The frequency resolution at a data length of 2048 will be 1/800 of the frequency range.
At 10kHz and 1kHz, it will be 12.5Hz and 1.25Hz, respectively.
Strictly speaking, it is slightly different, but for example, when looking at the spectrum at 500Hz, that spectrum displays the effective values of the bandwidths of 12.5Hz and 1.25Hz, so the 10kHz range will have larger values.
Displaying in PSD means that the spectral values are shown as 1/12.5 and 1/1.25, so the difference in the magnitude of the spectrum due to the frequency range becomes smaller.

Chapter of the relevant instruction manual

5.8.3 Power Spectral Density / Energy Spectral Density