| 摘要 |
<p>Method of detecting points of corrosion in a buried metal element; e.g. a pipe, incorporates carrying out, while the pipe is under a cathodic protection potential, an exact measurement of the potential between a point on the ground vertically above a point of electrical leakage, localised by conventional techniques, and a point 2-10 m away, pref. laterally in relation to the axis of the pipe. Those points of escape showing the lowest potential are points of probable corrosion. Those points of leakage are subjected to a further test. The cathodic protection is cut off for a period and a measurement is made to determine the sense of the potential difference between a point on the ground vertically above such a point, and a point remote transversely with respect to the axis of the pipe. The point is considered as a corrosion point with a high degree of certainty if it shows as an anode with respect to the other point. The probable points of corrosion may be determined, if only the potential is measured, and the certain points of corrosion may be determined, if the sign is measured. Prior art methods allow only possible points of corrosion to be determined, in a short space of time.</p> |
