Selection of electrodes for monitoring protection systems of ships’ steel hulls and machinery

The article considers the problems of ship structures exposed to adverse conditions, which contribute to the failure of important mechanisms and reduce the service life of steel parts of machines. One of the most important reasons for the ship structures wear is corrosion. The experience of choosing the electrodes to control the sacrificial protection systems on board ships is presented. There are presented the results of measuring the potential of the hull of the boat ROOM 52-22 at a given control point, using a multimeter MASTECH MY 62 and two control electrodes. The first control electrode is of in-house design; it was made of electric carbon product for electric machines. A standard portable silver chloride reference electrode was used as a second electrode. Both electrodes have been in operation for 3 years. The vessel under consideration was in a long-term parking mode. Control measurements were performed from 23.05 - 07.07.2019, while monitoring the potential of the hull three times a day using several parallel measurements. The time interval between parallel potential measurements made ≈ 5 seconds. The potential of the hull was measured by a specially trained operator. The accuracy of measurements was estimated using the coefficient of variation. Analysis of the studies justified that the accuracy of the control results of the protective anticorrosion systems on ships depends on the choice of the type of control electrode. It has been found that the efficiency of the silver chloride electrode has a strong impact on its operation life. The results of full-scale corrosion studies can be used by ship crews to justify the selection of control electrodes.