There are many opinions about adding water to the soil when obtaining the potential readings for cathodically protected underground pipelines and above ground tank bottom. The study is aimed to determine if this procedure is essential and if it is affected by different soil types. The study covered five petrochemical plants operating in the coastal region of Saudi Arabia. In this study we will compare the potential readings for the underground pipelines and aboveground tank bottoms which are cathodically protected by impressed current cathodic protection (ICCP) system or by sacrificial anode cathodic protection (SACP) system were compared The results showed that it is necessary to add water to the soil prior to taking potential readings of the structure.
Keyword: instant-offpotential, on-potential, impressed current cathodic protection (ICCP), sacrificial anode cathodic protection (SACP).