Water detector

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 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.

In addition, designers found the floor void a very convenient place to route other wet services feeding bathrooms, radiators and other facilities.

The computer room therefore became the early application for systems which would alert the operator to a leaking pipe in sufficient time for remedial action to be taken to prevent a disaster.

The mainframe computer room has largely been replaced with the Data Centre but the application has remained with almost universal use of "computer-room" style raised floors in nearly all new commercial and office construction.