Static Tube

The static tube senses the local static pressure in the flow and is schematically shown in Figure 2.1.The holes on the periphery of the tube should be sufficiently far away from the tip facing the flow so that the effect of distortion of flow by the probe on the static pressure being measured is minimized. This distance is preferably - , where is the probe diameter

The nose of a static tube is usually conical to streamline its surface and avoid flow separation. Three equally spaced holes are located on the periphery of the tube and the pressure recorded by the tube is an average over its circumference.