In a great number of cases, the leak tightness of products is decisive to functional capability and reliability. By the early detection of faulty parts in the manufacturing process, unnecessary costs can be prevented during manufacturing and following the delivery of products. Reliable leak testing is the most effective measure against complaints or recall campaigns, and the associated loss of image. Also in terms of product liability, leak testing is frequently an indispensable component of quality management. A decisive factor here is always selection of the right process and correct test criteria. But control of testing processes and the documentation of results also affects the sustainability of a leak test. All of these factors make leak testing a complex topic area. ZELTWANGER Dichtheitsprüfung has therefore made it a mission not only to construct appliances but also to devise individual, complete and need-driven leak testing concepts for its customers.