LN2 trap maintenance is simple. The LN2 should be kept at a constant level, since wide variations will cause some gases to evaporate as the trapping surfaces warm. LN2 level controlling devices are strongly recommended. Oil mist eliminators are designed to stop these aerosols. Typically, they contain a metal or nonorganic wool that makes the gas's path too torturous for the heavy aerosol articles to follow.
More recent designs use electrostatic fields to destroy the droplets.
Oil mist eliminators are generally attached to a pump exhaust port to allow captured oil mists o drain back into the pump. It cannot be overemphasized that the gases from any semiconductor process systems are extremely hazardous. Oil mist eliminators will not trap these gases. They must be vented Properly to the outside air. However. mist eliminators reduce the quantity of oil released into the environment and should be used on all mechanical pump installations.