High pressure sight level indicators (glass level gages) are designed to allow maximum pressure ratings regardless of glass size. These gages resist torsional stresses exceptionally well to provide a process gage for the most demanding applications. Units are used in direct reading liquid level measurement for high pressure tanks applications in the petroleum, chemical, natural gas and general process industries. They are not recommended for steam/water applications.
There are 2 high pressure indicator models: the Model RH-Reflex High Pressure and Model TH-Transparent High Pressure.
Reflex gages (RH) have a single vision slot in which light can enter the chamber. Above the liquid level, light is reflected and usually appears silvery. Area where liquid level is filled becomes transparent or dark/opaque depending on the medium being observed. Transparent gages (TH) have a vision slot on both sides of the chamber. Light enters on the opposite side of the observer so both the level of a liquid and characteristics can be seen. For observation in dark environments, illuminators are available for use with transparent gages.