Tuesday Tool Bioassay Edition

This Tuesday's tool is the voltage tester.  It's a little doohickey with a probe that you stick in the ground, connected by a wire to a little box with a metal hook that you hang onto an electric fence.  If the fence is "hot", then the box lights up.  The stronger the voltage, the more lights.  You use this to see if your electric fence is working like it's supposed to.

You can also use a ram for the same purpose.  If he's scratching his head, flossing the gap between his horns with what is supposed to be the hot wire, then you can be pretty sure that your fence isn't working properly.