The FFT window will appear and is shown below.
There are two pairs of cursors which may be used to measure differences in frequency. To the top of the cursors are marker blocks 1 and 2 for each active trace on the chart. To move a cursor, place the mouse pointer over the marker block you wish to move, and holding down the left mouse button drag the cursor to the point you wish to measure.
Channels can be made active or inactive by clicking on the ChA and ChB buttons. The coloured panel on the button is illuminated when the channel is active.
The units for the vertical scale may be changed between linear and logarithmic units by clicking on the blue area beneath the chart next to the word "Amplitude".
When the zoom function is active, the scroll bar at the bottom of the plot area may be used to scan through the FFT data.