Which measurement device is characterized by a flexible tube that responds to pressure changes?

The Bourdon tube is a mechanical device used primarily for measuring pressure. It consists of a curved, flexible tube that straightens out or changes shape as the internal pressure changes. This mechanical movement is then translated into a rotational movement that can be displayed on a dial or gauge, providing an indication of pressure.

This design is particularly effective because the Bourdon tube can accurately respond to small pressure fluctuations, making it a reliable tool in various industrial applications. Its straightforward construction and reliable function make it widely used in pressure measurement for liquids and gases.

While other devices mentioned, such as manometers and transducers, can also measure pressure, they operate on different principles. Manometers utilize liquid columns to indicate pressure, and an inclined manometer provides more sensitivity for low pressures by having a greater liquid column height change. Transducers convert pressure into an electrical signal, which is a fundamentally different approach from the mechanical response of a Bourdon tube.

Thus, the Bourdon tube is specifically characterized by its flexible tube design that directly responds to pressure changes, distinguishing it from the other options presented.