power meter

So I saw this in a magazine at work today: Jacarta Current Clamp by eveares posted 25 Sep 2017 at 8:57 PM The PDF on it is here: http://www.jacarta.com/wp-content/uploads/2016/07/Jacarta-intelliAmp-2016.pdf Apparently, it can measure power and current by simply clipping it over an active and...