1401. Which of the following direct reading gauge types is the most popular type used for local display of pressures in the engine room?

Bourdon tube type gauges are the industry standard for local pressure indication in engine rooms due to their robustness, accuracy, and wide pressure range; they utilize a curved metal tube that straightens with increasing pressure, moving a pointer on a dial, unlike bellows, diaphragm, or helix/spiral tube gauges which are suited for different, more specialized applications.