Water detection sensors are the heart of a leak detection system. Sensors are chosen based upon the site conditions and the level of cover required. Probes or plate sensors offer localised water detection. Where Sensing cables offer a more distributed leak detection field. Sensing cables can be run around the perimeter of plant such as pumps and tanks and can detect a water leak at any point along there length. There are other forms of sensors such as Infra-Red Optical sensors for Fuel leak detection and Float switches for high and low level detection in tanks and bunds. Tundish sensors can also be used to monitor Toilet Cistern overflows and overflow vents from water cylinders and tanks.