• A pitot tube is a simple fluid pressure measuring instrument that when coupled for example with a U-Tube manometer can be used to measure static, dynamic and/or total (or stagnation) pressure based on its configuration.

• The simple pitot tube used to measure the stagnation pressure consists of a tube pointing directly into the fluid flow. The moving fluid is brought to rest as the flow stops due to stagnation at the apex, leading to a pressure transmission through the static fluid in the tube.This pressure is the total pressure.

The tube when placed with a tap perpendicular to the flow helps to measure the static pressure of the fluid

• Similarly when the above two tappings are connected across a differential manometer, one can obtain the dynamic pressure, which is the difference between the Total and Static pressures of the fluid. Mathematically, Total pressure (PO) = Static pressure (P) + Dynamic pressure $(\rho v^{2}/2)$.