| 摘要 |
<p>The detection system is intended for flat roofs, bridge decks etc. and comprises an arrangement of electrical conductors between the substrate, such as concrete, and the sealing overlay, e.g. a water-proof membrane. When water leaks through the seal, the electric resistance of the conductors changes. Alternately the water may connect mutually isolated conductors causing a short circuit between them so that, when the isolation resistance is measured by passing a current pulse, its value is less than under normal conditions. Both methods may be employed together and the results indicated by both compared to increase the reliability with which leaks are detected. The arrangement of conductors may be broken down into subarrangements to facilitate localising the leak.</p> |
