Question

What is a "gauge"?

Answer 1

A gauge, in science and engineering, is a device used to make measurements or in order to display certain information. A wide variety of tools exist which serve such functions, ranging from simple pieces of material against which sizes can be measured to complex pieces of machinery. Depending on usage, a gauge can be described as "a device for measuring a physical quantity", for example, "to determine thickness, gap in space, diameter of materials, or pressure of flow", or "a device that displays the measurement of a monitored system by the use of a needle are pointer that moves along a calibrated scale".