The Electrical Conductivity Tester is a simple device that allows students to test different materials to see whether or not they conduct electricity. The material to be tested is clipped into a pair of quarter inch fuse holders. A probe wire is then used to attempt to pass electricity through the material. If the material conducts electricity, a small light emitting diode (LED) turns on. If the material is non-conductive, the LED remains off.
The main body of the Electrical Conductivity Tester is constructed from sections of 1 × 2 white pine and 1/4" plywood. While this set of instructions describes a device which can accommodate four test materials, the design can easily be changed to handle any number of test materials. The Electrical Conductivity Tester is powered by two AAA batteries. A small ballast resistor is used to limit the current provided to the LED.