The coefficient of discharge of a sharp-edged orifice is determined at one set of conditions by the use of an accurately calibrated gasometer. The orifice has a diameter of 20 mm, and the pipe diameter is 50 mm. The absolute upstream pressure is 200 kPa, and the pressure drop across the orifice is 82 mm Hg. The temperature of the air entering the orifice is 25?C, and the mass flow rate measured with the gasometer is 2.4 kg/min. What is the coefficient of discharge of the orifice under these conditions?