INTRODUCTION.

Flood detector also known as water detector 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 centres, trading floors, banks, archives and other mission-critical infrastructure.

The water leak detection industry is small and specialised with only a few manufacturers operating world-wide. 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 mm 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 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 metre resolution over a complex network of cables running several kilometres. This functionality reduces the downtime and potential damage caused by inaccurate reporting that was common with older analogue based systems.


below is the circuit diagram and parts needed


R1                   10K ohms resistor
R2                   10K ohms resistor
R3                   10K ohms resistor
R4                   1K ohms resistor
R5                   10K ohms resistor
R6                   1K ohms resistor
C1                   100nF cap
Led1                5mm green led
Led2                5mm red led
D1                   4V7 zener diode
Piezo               Piezo HPE-120
VR1                78L05 regulator
IC1                  12F683 SOIC microcontroller from Microchip
S1                    Push button
 
Others:
Box
9V battery clip
PCB
Metal strips
Hex program for the microcontroller