Electric Field Vector Mapping
About Low Voltage Vector Mapping
Electric vector mapping is a cutting edge technology that is redefining the art of leak detection and quality assurance in low-slope roofing and waterproofing systems. Vector mapping is a method of electronic leak detection that pinpoints breaches in the roof membrane by tracing the flow of an electric current across the membrane surface. Already Europe’s most widely-used method for detecting roof leaks, vector mapping is rapidly being adopted by manufacturers, contractors, and specifiers in the United States.
Vector mapping eliminates the dangers and potential damage inherent in traditional flood testing. Unlike the interpretive process of water, flood, infrared, or nuclear testing, vector mapping detects membrane faults directly. It is ideal for quality and warranty assurance needs, for leak testing of green (vegetative) and ballasted roofs, and for leak detection in all low-slope roofing systems in which the membrane is not electrically conductive and the deck can be electrically grounded. Even pinhole leaks invisible to the naked eye can be pinpointed with vector mapping, and repairs can be made on the spot and immediately retested to ensure watertight results.
Low Voltage Vector Mapping
In low voltage vector mapping, the surface of the roof membrane is moistened (not flooded) to create an electrically conductive medium. A conductive wire loop is laid on the membrane around a section of the area to be tested. One lead from a pulse generator is connected to this wire loop perimeter. The other lead from the generator is connected to the structural roof deck. Leaks or breaches in the membrane are detected when the electric current flows across the membrane and down through the breach to the deck, completing the circuit. The technician uses two probes connected to a receiver to determine the direction of the electric current and precisely locate the breach.
Low Voltage Vector Mapping vs High Voltage Electronic Leak Detection
Both High Voltage ELD and Low Voltage Vector Mapping can be employed on most roofing and waterproofing membranes. However, roofs with overburden (vegetation, pavers, ballast, etc.) must be tested with Low Voltage Vector Mapping, because the High Voltage brush sensors must be able to make direct contact with the membrane. Neither method can reliably inspect black EPDM membranes, which contain carbon black and are therefore electrically conductive. Both techniques are safe, cost-effective and highly reliable, allowing problem areas to be quickly marked, repaired, and re-tested.