| 摘要 |
At controlled intervals, alternating low- (20) and high- (21) electrical potentials are applied to metal wire laid along the pipeline. A leak tracer- or indicator-substance is produced electrolytically, by the action of the high- but not the low electrical potential, on the leaked fluid. An Independent claim is included for corresponding equipment. The collection line permeable to the electrolytically-released substance is connected to a pump and sensor (at opposite ends), and has the metal wire along it. This is connected to the negative pole of a direct current source under time control as described. Preferred Features: High potential is maintained for a short interval; low potential for a long interval, in alternation. The long interval is 2-30 times the short. The low potential suffices only for cathodic protection of the wire. The high potential is adequate for electrolysis in addition, at the end of a long metal wire. In the equipment used, the positive pole of the direct current source is earthed. At intervals along the metal wire, there is no insulation around its circumference
|
