The Sewerin Variotec 460 Tracer Gas leak detector locates leaks where acoustical systems cannot, e.g., extremely deep pipe, loud ambient industrial sites, etc., or where newly installed water systems fail air pressure testing. Detecting water leaks using tracer gas involves injecting a mixture of 95% nitrogen (N₂ as carrier gas) and 5% hydrogen (H₂) as the traceable/detectable agent. The H₂ gas escapes through the leak and is detected above ground by the sensitive Variotec 460 instruments specialized sensor. H₂ tracer gas is non-toxic and non-corrosive, therefore permitted for use in all drinking water systems. H₂ tracer gas is environmentally neutral and permeates all cover layers such as asphalt, concrete, and other seal coats. Hydrogen (H₂) is the lightest and smallest known element on the periodic table; therefore, it will always take the shortest route from the leak in the pipe to the surface, pinpointing a water leak on any surface or ambient scenario possible.