LS300A portable flow rate meter (hereinafter referred to as portable flow meter) is the nanjing zhuoma electromechanical co., LTD., specifically for hydrological stations, factories and mines, environmental protection monitoring station, farmland irrigation and drainage, hydrogeology survey and other departments in the field of velocity of flow in open channel flow measurement. LS300 - A type of intelligent flow velocity meter rotors can form A complete set of new type velocity sensor, the sensor is to adopt advanced technology of the latest developed at the end of 2004, rotary pulp spiral Angle, pitch, production process and material are redesigned, rotary pulp diameter of 15 mm and 12 mm respectively (rotors reflective surface adopts advanced electroplating process, wear resistance, strong signal), the starting velocity of 1 cm/s or less, starting speed, speed measuring range, linearity, concentricity, rate coefficient and the mean square error indexes than in the past such as sensor has greatly improved and improve.