What does a bourdon tube consist of?

A bourdon tube consists of a curved tube with an oval cross-section. This shape is integral to its function as a pressure measuring device, commonly found in pressure gauges. When pressure is applied inside the tube, it causes the curved tube to straighten or change its curvature. This deformation is then translated into a rotational movement to indicate pressure on a dial. The oval cross-section is crucial because it provides the necessary strength and sensitivity required for accurate pressure readings.

The design of a bourdon tube takes advantage of the material's properties to respond predictably to changes in internal pressure, making it an effective choice for measuring a wide range of pressures in various applications. The other options do not accurately describe the structure and function of a bourdon tube, which is specifically tailored for pressure measurement engineering.