Rainfall Resistivities

A total of 721 observations has been made at eight locations throughout the United States to determine the resistivity and rate of fall of natural rain. The results indicate that approximately a third of the samples show resistivities lower than the standard 7,000 ohms-inch used in laboratory tests. Minimum value recorded was 100 ohms-inch and the maximum value 166,000 ohms-inch. The maximum rainfall rate recorded was 0.076 inch per minute, which is actually less than half of the standard laboratory rate of 0.20 inch per minute.