Since the purpose of a transfer function is to compare signals you might want to compile a list of measurements and them compare them at the same time. Transfer function tools allow for saving data, managing what shows in the measurement window and even to recall the data at a later time if you save your measurements.
SpectraFoo calls these saved measurements “snapshots” and you manage them in the overlay list window.
Here is an example of a overlay I recently made using snapshots.
In order to keep track of the difference (if any), I took a snapshot via the “TAKE SNAPSHOT” button at the bottom left side of the TF window.
In that same area is a button to display the snapshot overlay list.
When you’re saving snapshots and then comparing them, it’s sometimes helpful to discontinue the measurement process and clear away any remaining data on the screen so you’re only looking at snapshots. These are the places to stop the measurement and clear the window.
All of the functions mentioned above can be achieved with key commands:
This is what it looks like when you turn off the measurement tool & clear the realtime data while showing all the snapshots.