FYI: no one's power is stable, its always in a state of change, some worse than others. With that said, various power conditions will tame that change and stabilize it. My Equi=Tech 2Q has two different LED's, I can monitor incoming power or the outgoing power to my components.
I've also used a multimeter along with my Core Power Technologies Equi=Core 1800 and see constant voltage. I'm sure the same would be true with other good power conditioners.
I've also used a multimeter along with my Core Power Technologies Equi=Core 1800 and see constant voltage. I'm sure the same would be true with other good power conditioners.