Electrolytic corrosion measures

The Bureau of Standards has recently announced the development of an instrument known as the “earth current meter” which measures corrosion of underground structures. In connection with this announcement it is stated that the determination of the seriousness of corrosion of underground structures due to stray electric currents has been difficult and the results unsatisfactory because there has been no simple method of measuring the amount of stray current at the point where electrolysis is suspected. For this reason, engineers of the Bureau have endeavored to develop an instrument which will indicate directly the strength of the current in the earth at a given point. It works upon the theory that the rate of corrosion is directly proportional to the strength of current flowing from a structure. Such an instrument would indicate directly whether the structure under test was in danger from electrolysis. The instrument is described in detail in technical paper No. 351, which also describes the various ways in which it may be used to determine electrolysis conditions.