Why is the Blue Gauge Called a Compound Gauge: A Quick Answer The blue gauge commonly referred to as a compound gauge occupies a unique position in the realm of instrumentation. Unlike typical pressure gauges that measure only positive pressures, the compound gauge is designed to read both positive and negative pressures (vacuum). This dual capability is the fundamental reason behind its name—“compound.” The term “compound” signifies the gauge’s ability to measure a compound range of pressures, encompassing vacuum, atmospheric, and positive pressure levels. In this article, we will delve into the mechanical principles, applications, and distinctive features that qualify the blue gauge as a compound gauge. https://www.ourmechanicalworld.com/archives/6166