A comparison is made between weather data and cathodic protection survey data of a four-mile section of 20-inch bare pipe line in southwestern Pennsylvania over a period of five years. The relationship between rectifier current output and rainfall, soil temperature and mean daily temperatures are considered.
It was found that temperature has little or no effect on cathodic protection required. Precipitation of more than one-half inch, when it occurs in the form of water, makes a definite change in the cathodic protection current requirement. The effects of precipitation are transient, current requirement returning to normal as soon as the rain stops. Precipitation in the form of snow has much less effect upon cathodic protection than does its water equivalent. 8.9.3
