Seems like I am always testing conductivity around the house. I test light bulbs, fuses, circuit connections, diodes, etc. I have a several good multimeters but what I want to build is something that would be small, battery powered, with a meter or 2 digit display. The ideal device would show a poor connection (not just a nine volt battery, resistor, and a resistor) such as a resistance of 10-20 ohms - when a connection was not quite as good as it should be. It should insert very little voltage into the circuit as not to damage delicate parts. Finally, it should be so simple to use that my wife could use it. (I'm gonna be in trouble for saying that - aren't I?) Any schematics on hand?