A pitot tube's a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot in the early 1700s and was modified to its modern form in the mid 1800s by French scientist Henry Darcy. It's widely used to determine the airspeed of an aircraft and to measure air and gas velocities in industrial applications. The basic pitot tube consists of a tube pointing directly into the fluid flow. As this tube contains fluid, a pressure ca… (More on Pitot)