Low Voltage / Wet Electronic Leak Detection

SET-UP

• A wire loop, to act as a conductor, is placed directly on the membrane or the membrane's protection course around the perimeter of the area to be tested.
• One of the two leads from a pulse generator is connected to this wire loop conductor.
• A second lead from the power supply is grounded to the structural deck. The surface of the waterproofing must be wetted (not flooded) to provide an electrically conductive medium.

 TESTING

• The power supply generates the potential difference between the wet roof surface and the roof deck, which is "earthed" or grounded - essentially producing two electric plates.
• If there are any "leaks" or breaches through the roofing/waterproofing membrane, which acts as an electric insulator, the small electric current will flow across the membrane surface and down through the breach, completing the circuit between the two "electric plates."

REPORTING

• A technician operates the receiver, by systematically moving it along the membrane in order to find even the smallest breach or leak. Once the breach is located, it is marked, photographed, and cataloged.  The breach can then be repaired and quickly retested.

BUT WHY LOW VOLTAGE AND NOT HIGH VOLTAGE?

Both methods of testing are equally effective.  It is the job site conditions that dictate the method of Electronic Leak Detection that will be used.