Roots gas flowmeter

The utility model discloses a Roots gas flowmeter, which can prevent impurities from entering the Roots gas flowmeter and is convenient in disassembly and maintenance. An air inlet and an air outlet of the flowmeter are respectively provided with an annular mounting groove; a filtering component is installed in each of the mounting grooves; the filtering component comprises a filter screen and a holding frame made of elastic materials; the filter screen is in seal connection with the holding frame; the holding frame is in interference fit with the inner wall of the mounting groove; the filter screen is dome shaped and protruded towards the outer side, and the top-most part of the filter screen is lower than a flange plane. According to the Roots gas flowmeter disclosed by the utility model, the filtering components are installed at the air inlet and the air outlet of the Roots flowmeter, so that the fault of blocking the flowmeter due to the impurities entering the flowmeter body in the transportation and installation process can be avoided, and the use reliability can be improved. Meanwhile, the elastic holding frame in the filtering component is in interference fit with the inner wall of the mounting groove, so that the Roots gas flowmeter can be prevented from falling off in the transportation and installation process, and the later maintenance and disassembly are convenient.