This unit is used to vacuum–exhaust laser gas from the gas circulating system such that its pressure falls to that used for laser oscillation. Also, within this unit, a small amount of circulating gas is constantly being exchanged, to prevent degradation of the circulating gas.

  When first starting the oscillator, check that gas is output from the gas outlet of the oscillator. Depending on the parameter settings, it may take as long as one minute before gas is output. If no gas is output, the exhaust pump rotation may be reversed. If this situation is left uncorrected, the exhaust pump may ultimately start to make an abnormal sound, and the thermal switch may trip. In the worst case, the gas circulating

 When the operation time reaches every 4,000 hours or 2 years whichever comes first, or the exhaust capacity is lowered, replace the exhaust pump filter. A clogged exhaust pump filter may cause a whitish smoke of oil mist to come out of the pump or lower the exhaust pump capacity.