Vacuum pressure is limited by the following three factors.


  1. Carrier gas: Depends on analytical parameters.

  2. Gas desorption from the surface of the chamber and parts: Decreases slowly. It takes much time for this contribution to decrease.

  3. Limitation from pump performance. Usually, pressure less than 10-3 to 10-4 Pa is required near the rod and the detector
Limitation Factors of Vacuum