/diy/ - Do It Yourself

So I use one of these for work. what's the deal with the class II or double insulated test? I've never seen it fail anything (even though when I plug the alliance in after it might spark or trip the power).

does it really not fail anything? the class ii button even passes thin air when nothing is plugged into the machine.

is there even any point in plugging the appliance in or doing the machine test for class ii items? seems like a waste of time since right know the result it will give me. may as well just throw a tag onto it