What standard pressure reading does a Bourdon-tube typically provide?

A Bourdon-tube is designed to measure gauge pressure, which is the pressure relative to atmospheric pressure. This means it indicates how much pressure is above the atmospheric pressure surrounding the sensor. The key characteristic of gauge pressure readings is that they don't take into account the atmospheric pressure itself; thus, if the gauge reads zero, it indicates that the pressure in question is equal to atmospheric pressure.

In practical applications, Bourdon-tube gauges are widely used in various industries for monitoring pressures in systems like gas turbines, hydraulics, and plumbing. They convert the pressure exerted on the tube into a rotational movement that drives a pointer on a dial, visually indicating the pressure level.

The other options, such as absolute pressure, vacuum pressure, and static pressure, relate to different types of pressure measurements. Absolute pressure measures pressure relative to a complete vacuum, vacuum pressure measures pressure below atmospheric pressure, and static pressure refers to pressure within a fluid at rest. Each of these serves a specific purpose but differs fundamentally from the gauge pressure provided by a Bourdon-tube.