https://en.wikipedia.org/wiki/Kill_A_Watt https://en.wikipedia.org/wiki/Kill_A_Watt Works good IME, but you have to plug it into the wall first. Sometimes if y

https://en.wikipedia.org/wiki/Kill_A_Watt https://en.wikipedia.org/wiki/Kill_A_Watt Works good IME, but you have to plug it into the wall first. Sometimes if you plug the appliance in, and then plug the KAW in, it will miscalibrate