Probing an AC circuit with an Oscilloscope - Is this feasible and safe?

[ThermallyFrigid]

Let's say you had an SMPS you were wanting to probe with your oscilloscope.
Obviously, incorrectly using non isolated probes could cause serious damage to the oscilloscope or worse.

So most people opt for an isolation transformer or something like the Micsig DP10013 High Voltage Differential Probe (or both)

But why wouldn't the following method be just as safe?

Using an inverter that is powered by a battery, to power either the oscilloscope or the SMPS circuit?
That way, the Earth is never directly connected to both the Oscilloscope and the SMPS circuit at the same time.

I am not certain this will work, it is a question?
Thanks

[EE4all]

That can add a safety factor sure, but there a other vectors and aspects to the safety. Yes, that is a vague answer on purpose, to make you think. Maximum limits on the scope itself are an aspect too. Safety for the gear AND MOST importantly, your health, is good to think about. An isolation transformer used wrongly can actually make things much more dangerous.

[bdunham7]

An isolation transformer used wrongly can actually make things much more dangerous.

The same goes for screwdrivers...

[bdunham7]

Using an inverter that is powered by a battery, to power either the oscilloscope or the SMPS circuit?

A battery powered inverter may functionally take the place of an isolation transformer, but there is a possibility of an increased hazard when you selectively ground a part of the DUT (SMPS in your case) to take a measurement since the whole inverter and battery may become live relative to ground. 

[EE4all]

LOL! Too true on the screwdriver. I put one all all the way through my hand not too long ago when it slipped.  Accidents can happen... try to avoid them with safety precautions and correct usage of the tools at hand.

[J-R]

Perhaps do you have enough channels to use the scope's math function as a differential probe?