What instrument is used to measure the velocity pressure of a flowing stream, converting velocity energy to pressure energy?

What instrument is used to measure the velocity pressure of a flowing stream, converting velocity energy to pressure energy?

• A. Pitot Tube
• B. Cavitation
• C. Steamer Connection
• D. Water Main

Answer: (A)

Velocity pressure is the dynamic pressure created by the motion of the fluid, so you need a device that converts that kinetic energy into a readable pressure signal. A Pitot tube does exactly that: it faces into the flow to measure stagnation (total) pressure, while a separate static port measures the ambient pressure. The difference between the stagnation pressure and the static pressure is the velocity pressure, which follows the relation q = (1/2) ρ v^2. From that, you can compute the flow velocity. This also explains why the Pitot tube is widely used for measuring flow in moving streams, giving a direct reading that translates velocity energy into pressure energy. The other options aren’t measurement devices for velocity pressure: cavitation is a flow phenomenon, steamer connection is a piping component, and a water main is a water supply pipe.

Velocity pressure is the dynamic pressure created by the motion of the fluid, so you need a device that converts that kinetic energy into a readable pressure signal. A Pitot tube does exactly that: it faces into the flow to measure stagnation (total) pressure, while a separate static port measures the ambient pressure. The difference between the stagnation pressure and the static pressure is the velocity pressure, which follows the relation q = (1/2) ρ v^2. From that, you can compute the flow velocity. This also explains why the Pitot tube is widely used for measuring flow in moving streams, giving a direct reading that translates velocity energy into pressure energy. The other options aren’t measurement devices for velocity pressure: cavitation is a flow phenomenon, steamer connection is a piping component, and a water main is a water supply pipe.