DMF drilling gas flow meter is mainly used for drilling of coal seam gas in underground coal mine seam drilling natural gas flow or anti-conflict test becoming a q value of the initial velocity measurements. Can also be used for other gas flow rate (velocity) measurement. The instrument has automatic display, storage, timing, time-sharing and continuous flow (flow rate) and cumulative function. Small size, light weight, easy to operate, the explosive gas environment in the coal mine work. Also applies to the work of the laboratory or other place of the gas flow rate (velocity) measurement.