Vacuum pump

A vacuum pump is a mechanical compressor that operates at less than atmospheric pressure. A vacuum pump can be a positive displacement pump that transports a gas load from an inlet port to and outlet, or exahust, port. Vacuum pumps can also work on a momentum transfer[?] principle, cryogenic entrapment[?] principles as well as the positive displacement[?] principal.

Types of Vacuum Pumps

• Transfer
  • roots blower[?]
  • rotary compression[?]
  • Diffusion pump
  • turbomolecular pump

• entrapment pump[?]
  • ion pump
  • cryopump