What is the function of a Bourdon tube in pressure measurement?

The function of a Bourdon tube in pressure measurement is to expand and contract in response to pressure changes. This is a fundamental principle behind its operation. A Bourdon tube is a hollow, curved metal tube that reacts to internal pressure. When the pressure inside the tube increases, the tube tends to straighten out due to the force exerted by the pressure. Conversely, when the pressure decreases, the tube returns to its original curved shape. This mechanical movement translates into a readable indication on a dial or gauge, allowing for accurate measurement of pressure levels.

The design of the Bourdon tube leverages the elastic properties of the material from which it is made, typically brass or stainless steel, which ensures that it responds reliably to pressure variations. The relationship between the pressure applied and the resultant movement of the tube forms the basis for many pressure gauges used in various industrial and laboratory settings.

While the Bourdon tube is critically involved in pressure measurement, other options do not reflect its actual function. The tool does not measure differential pressure directly, nor does it serve as a fluid barrier or measure temperature. Therefore, the correct characterization of a Bourdon tube's role is its capacity to expand and contract in response to changes in pressure.