Abstract: According to the special requirements of engineering experiment,the importance and investigation of propeller folw meter are expatiated in engineering model test.Emphasis is given to introducing the application of Model HD-4B computer flowmeter in measuring slowly changing unsteady flow velocity in positions and quickly measuring steady flow velocity,and the principles of the meter,measurement error analysis,sensor sculpture research,comparison test and its application.

Key words: flow meter, period method, unsteady flow, flow turbulence, propeller