Implosion monitor for vacuum systems

As fast sensors for implosions or leaks in big vacuum systems, small electret microphones are well suited. They generate signals within <10−4 s after arrival of the gas, which can be used to close fast valves or protect components in the vacuum system. The microphone response was tested with small implosions of normal air and hydrogen at different gas (pressure×volume) quantities. The effect of mechanical shocks and mechanical vibrations on the microphone response can be made negligible.