To... itself? Go measure something. You now have a reference!
If you scratch out the labels of your car speedometer and forget which is which, it still measures speed. 80 is still 33% faster than 60, regardless of the units.
I suspect your questions would be answered better by playing around with the tool in question for a few minutes anyway, as you seem to be asking about capabilities the tool does not purport to have.
To what?
I talked about driving a car. Miles and hours are an absolute reference. We still have no absolute reference for Speedometer.