To measure grounding, use a multimeter to test continuity between the outlet's ground pin and a reliable source of ground, like a metal water pipe. If the reading is low, the outlet has proper grounding. Another method is measuring soil resistivity, using techniques like the Wenner Four-Point Probe or Fall-of-Potential Test. A properly installed lightning protection system includes a roof network, down conductors, equipotential bonding, a grounding system, and surge suppression devices.