Which type of flow meter has a disc centered in a pipe and is positioned perpendicular to fluid flow?

The flow meter that features a disc centered in a pipe and positioned perpendicular to the fluid flow is the target meter. This type of meter operates based on the principle of measuring the force exerted by the fluid on a target surface. When fluid passes through the pipe, it strikes the target disc, and the force generated is proportional to the flow rate. This relationship allows for accurate measurement of the flow.

Target meters are designed to provide reliable performance in a variety of conditions, including those with changes in flow dynamics. They are particularly useful in applications where a straightforward and effective means of flow measurement is required, offering an advantage over other types of flow meters.

In contrast, the other flow meters mentioned operate based on different principles. A rotameter measures flow through the vertical displacement of a float in a tapered tube, while a turbine meter uses rotor motion that correlates with flow rate. Flow nozzles, on the other hand, create a pressure drop by constricting the flow, which is then used to calculate the flow rate based on pressure differentials. Each of these has its specific operational criteria and applications that differ from the target meter's design and function.