Water detector
From Wikipedia, the free encyclopedia
A water detector is an electronic device that is designed to detect the presence of water for purposes such as to provide an alert in time to allow the prevention of water leakage. A common design is a small cable or device that lies flat on a floor and relies on the electrical conductivity of water to decrease the resistance across two contacts. The device then sounds an audible alarm together with providing onward signaling in the presence of enough water to bridge the contacts. These are useful in a normally occupied area near any infrastructure that has the potential to leak water, such as HVAC, water pipes, drain pipes, vending machines, dehumidifiers, or water tanks.
Water leak detection is an expression more commonly used for larger, integrated systems installed in modern buildings or those containing valuable artifacts, materials or other critical assets where early notification of a potentially damaging leak would be beneficial. In particular, water leak detection has become a necessity in data centers, trading floors, banks, archives and other mission-critical infrastructure.
The water leak detection industry is small and specialized with only a few manufacturers operating worldwide. The original application was in the void created by "computer room" floors in the days of large main-frame computer systems. These use a modular raised floor based around a structural "floor tile" usually 600 millimetres (24 in) square and supported at the corners by pedestals. The void created gave easy access and routing for the mass of power, networking and other interconnecting cables associated with larger computer systems - processors, drives, routers etc. mainframe computers also generated large amounts of heat so a void under the floor could also be used as a plenum to distribute and diffuse chilled air around the computer room. The void therefore was likely to have chilled water pipes running through it along with the drains for condensates associated with refrigeration plant. In addition, designers found the floor void a very convenient place to route other wet services feeding bathrooms, radiators and other facilities.
A leak occurring within a floor void would therefore go unnoticed until the hydrostatic head of pressure meant that the water found its way through to floors below where its dripping through the ceiling would be noted or, and more disconcerting, the water would penetrate the joints and connectors of the power or network cabling and cause system failure from short circuit.
Current digital water leak detection systems can locate multiple water leaks to within 1 meter resolution over a complex network of cables running several kilometers. This functionality reduces the downtime and potential damage caused by inaccurate reporting that was common with older analogue based systems.
Water leak detection systems can be integrated with Building Management Systems using multiple protocols such as Modbus. Using SNMP protocols leak detection systems can inform IT staff in charge of monitoring data center and server rooms.
