Conductive probe for sensing liquid levels in drainage systems

摘要

A probe for detecting the liquid level in drainage systems (e.g. sewerage systems) comprising at least a pair of stainless steel electrodes 10, 20 wherein each electrode is substantially surrounded by a hollow sheath 100. The sheath is open at its bottom end to allow liquid to enter and rise up within the sheath and comprises a vent (e.g. a longitudinal slot) to allow expulsion of air displaced by rising liquid levels. The device may comprise a third shorter electrode 30, wherein one electrode is common and the other two are arranged to sense a level of retained liquid and a flood condition respectively. The electrodes are provided with a plurality of pre-weakened portions along their length to alter the electrode length. The device and system comprises a means for transmitting readings (e.g. antenna 210) from the probe to a remote station for monitoring the condition of a drain network.