The Venturi meter has three main holes. These holes can be named as fluid inlet,
outlet, and air valve. As seen from Figure 1, fluid is supplied from the inlet (from
4
supply) and goes out to the measurement tank from the outlet. Flow velocity is
adjusted with a control valve. The order of measured pressure can be changed
with changing the air pressure in the manometer. Air valve hole is used to
change and set the air pressure of the manometers. Technical details of the
Venturi meter can be seen in Table 1