| 摘要 |
<p>PURPOSE:To enable a prevention of accident of making holes by a method wherein an upper part of a tank is provided with a corrosion detecting electrode and when water is flowed into the inside part of the electrode, an alarm is produced. CONSTITUTION:When an enamelled part of a tank 1 of steel plate has a minute volume of melting as the time is elapsed and the pin holes are increased in their sized, a current density in the steel protective pipe 9 for the corrosion detecting electrode 5 arranged at the upper part is initially decreased and reduced below the desired corrosion current density and then the corrosion is started to occur. If a wall thickness of the steel protective pie 9 is made thinner than that of the steel plate tank 1, the steel protective pie 9 shows at first a pin hole and water is flowed into the pipe at first. As a result, electric current is flowed between the water sensor lie 8 and the steel tank 1, a contact point of a relay 7 is operated to drive an alarm device 6 and so the accident of water leakage can be prevented.</p> |
