Seal testing, esp. for flat seals - detecting changes in electrical characteristics caused by defects using point or small area probe in electrical circuit

摘要

An electrical circuit is used to test the tightness of a seal. The circuit contains a voltage source (5) whose reference potential is the potential on the rear face of the electrically conducting medium (2). A measurement device (4) and a probe are also included in the circuit. The probe is applied to a point or small area of the open surface of the medium. The effect is a variation in the electrical characteristics of the seal if there is a defect in the test region of the probe. This is detected as a significant change in an at least one electrical parameter. USE/ADVANTAGE- Esp. for testing non-conducting flat seals, e.g. on liquid tanks and in tunnels. Installed seals can be tested in situ before tank or tunnel is filled or becomes operational.