Abstract: An electrolytic corrosion associated voltage integrating apparatus comprising a first terminal to be connected to an electric conductor, such as a gas pipe, water pipe, telephone cable or the like, installed in electrical contact with the earth and a second terminal to be connected to an earthed reference electrode; a solid state electrochemical potential memory device which exhibits a terminal voltage between an anode and a cathode linearly changing as a function of the charging or discharging quantity of electricity fed to the device and which is capable of holding the terminal voltage, said device being connected to the terminals to receive an input therefrom; a reference voltage source for compensating the said conductor-to-earthed reference electrode potential input for a potential difference developed between the said earthed reference electrode and the earth per se; and means for displaying the terminal voltage of the device.