Liquid Level Gauge (“sight glass” in old boiler terminology)

The term “sight glass” can refer to several types of units that allow observation of a process fluid or a feature inside of a pipe, tank or vessel. The following are the descriptions of units that are commonly referred to as sight glasses.

A liquid level gauge is an instrument that is used to monitor the fluid level in a tank or vessel. In old boiler related jargon, this unit had traditionally been referred to as sight glass. Currently, it is typically referred to as a liquid level gauge, a much more descriptive label.