Low vacuum pumps are those that can not produce a vacuum greater than 685.8 mmHg. The most commonly used are reciprocating piston or hermetic compressor used as a vacuum pump (reciprocating or rotary).
High vacuum pumps are capable of producing a vacuum well above 736 mmHg. They are of the type of sliding vane and the eccentric type.
Theoretically, a low vacuum pump will reach a maximum vacuum of 685.8mm and a high vacuum pump will reach a maximum vacuum of 760mmHg.
