This unit includes a transparent PMMA tank, a measuring device as well as a Pitot tube and twin tube manometers. An interchangeable mouthpiece is installed in the tank’s water outlet to facilitate the investigation of various openings. Five mouthpieces with different diameters, inlet contours and outlet contours are provided along with the unit. Pressure losses in the flow from tanks are essentially the result of two processes: the jet deflection upon entry into the opening and the wall friction in the opening. As a result of the pressure losses the real discharge is smaller than the theoretical flow rate. Different diameters as well as inlet and outlet contours of the openings can be studied. Additionally, the contraction coefficient can be determined as a characteristic for different contours. The issued water jet is measured using a measuring device. A Pitot tube detects the total pressure of the flow. The pressure difference (read on the manometer) is used to determine the velocity. The experimental unit is positioned easily and securely on the work surface of the EDC-FM-100HB base module. The water is supplied and the flow rate measured by EDC-FM-100HB. Alternatively, the experimental unit can be operated by the laboratory supply.