The device is used to measure the flow Measured in both liquid and gas. Works on the theory of numbers Nouri. Or the pressure difference. Like Orifice plate designed by venturi tubes with a pressure loss to a minimum. The funnel tube is extended. Characterized by an increase or decrease in the cross-sectional area of the venturi tubes are incrementally. The speed of the fluid changes occur slowly, resulting in a pressure loss is less compared to a Orifice plate or Nottingham Castle.