Multi-plug Power cord tester (HD-10B Tester)

A circuit tester is a device which is plugged into an electrical socket to make sure it is wired properly. A circuit tester has a series of lights that show the state of the wiring in the outlet, so the technician can verify that it has been installed properly.First, set your multimeter to voltage. Insert a probe into each slot (black lead on the left and red lead on the right). Then read the measurement. For a properly functioning outlet, the reading will be 110 to 120 volts.