Which type of flow measuring device is suitable for installation in a pipe that is flowing full?

The correct answer is the Venturi meter, which operates on the principle of fluid dynamics and is specifically designed to measure flow in a pipe that is flowing full. The Venturi meter consists of a tapered inlet, a throat, and a gradual outlet, which creates a pressure differential between these sections of the meter as fluid flows through. This pressure difference can be measured and used to calculate the flow rate based on Bernoulli's principle. The design of the Venturi meter allows it to function effectively when the pipe is full, as it relies on continuous fluid flow without air pockets, ensuring accurate flow measurements.

Other types of flow measuring devices, while useful in specific scenarios, may not be as universally suited for full pipe flow. For example, electromagnetic and ultrasonic flow meters can also measure flow in fully filled pipes, but they do so using different technologies that may require certain conditions to be met, such as the need for conductivity in the case of electromagnetic flow meters. Rotary flow meters typically work well for clean liquids and can measure flow but may not be suitable for all applications, especially in varying pressure conditions or for fluids with particulates. Thus, while they can function in full pipes, the specialized design and efficiency of the Venturi meter make it the most