For what reason are Bourdon tubes commonly used in pressure measurement devices?

Bourdon tubes are widely utilized in pressure measurement devices primarily due to their ability to accurately indicate pressure levels. The fundamental operation of a Bourdon tube relies on its design, which consists of a curved, hollow tube that straightens as pressure increases. This straightening movement is directly proportional to the pressure inside the tube.

As the pressure rises, the Bourdon tube expands, causing the end of the tube to move in a way that translates into a readable measurement on a dial or gauge. This mechanism allows for the conversion of pressure into a mechanical movement, making it highly effective for monitoring and displaying pressure levels in various applications, such as in hydraulic systems, gas pressure regulators, and industrial processes.

The other options do not pertain to the functionality of Bourdon tubes; for instance, measuring temperature changes involves different types of sensors like thermocouples or RTDs, while recording flow rates is typically managed with flow meters or other devices designed for that specific purpose. Gauging voltage, on the other hand, requires electrical measurement devices such as voltmeters. Therefore, the standout purpose of Bourdon tubes lies in their crucial role in indicating pressure levels.