These Sewerin products are specifically for locating under ground leaks using tracer gas. Using tracer gas is a tried and tested method of pinpointing leaks. It can be used in gas and water distribution networks, pipelines in buildings, heating systems, pressurized communication cables, gas-filled high voltage power lines, and landfill sites sealed with double membrane layers. It can also be used to test for leaks in industrial products such as pipes, pumps, engine blocks and airfoils. Detecting gas leaks by tracer gas involves feeding a mixture of 95% nitrogen (carrier gas) and 5% hydrogen into the pipelines or other equipment/ products being tested. The hydrogen escapes through the leak and is detected using the sensors incorporated into the Tracer Gas leak detectors.