I have aquired 3 Tripplite Inverters model PV-1000 FC. I was told that they are pure sine wave inverters, but on the front of them it says "square wave". Anyone have any experience or knowledge on the sine wave type. I am wanting to use them to power my home and would like something safe for TV's, Stereo, computers, and microwave. Other than hooking them to an Oscilliscope, is there any other way to check them.