ELD is a quality-control testing procedure designed to locate discontinuities in waterproofing and roofing membranes. ELD determines the location of the membrane discontinuities (breaches/seam voids) by applying an electrical current to the surface of the membrane. ELD can also be called: electronic water test, electronic breach detection, membrane integrity testing, membrane integrity survey, and electrical conductance testing. ELD can be low-voltage or high-voltage.