Pumps - Vacuum pump

Vacuum pumps are used to generate a vacuum. A distinction is made between vacuum pumps according to the vacuum they generate and their operating principle. Depending on their physical operating principle, vacuum pumps are divided into gas transfer vacuum pumps and gas-binding vacuum pumps. Different vacuum pumps or combinations thereof are used depending on the vacuum level to be achieved and the required pumping capacity. Different pump types have different areas of application depending on their function. To achieve low vacuum pressures, two pump stages are often required (for example, for pressures p < 10-3 mbar). The first pump (e.g., a rotary vane pump) generates a preliminary vacuum and is often referred to as the backing pump; the next pump is then connected to the recipient. Typical pump combinations consist, for example, of a positive displacement vacuum pump as backing pump and a turbomolecular vacuum pump.