AN APPARATUS FOR DETERMINING GAS FLOW IN VACUUM PUMP-MEASURING NOZZLE

Measuring nozzle is an appratus which is often used in the determination of the gas flow in roough vacuum pumps （such as water ring pump,reciprocating vacuum pump and sliding vacuum pump etc ）.This papes briefly describes the workingr principle of the nozzle and its calculating method and requirements of installation and operation,and also presents its measuring accuracy.