For increased electronic insulation strength, high-voltage relays are made vacuum or gas-filled, for example, as the dielectric strength of vacuum, sulfur hexafluoride or an inert gas is higher than air. Even in a vacuum or in an insulating gas environment, no oxidation of the contacts occurs, which in fact makes it possible to use copper or rhodium contacts capable of withstanding gigantic currents. To be able to be used in applications where space is "hot-switched" at low currents, we have come up with vacuum relays with contacts made of durable materials such as tungsten... Read More »inside the relay