Sight glass level indicators

How does a reflex sight glass level indicator work?

The principle of the reflex level indicator is based on the reflection of light. In the gas or steam phase, the light is reflected by the prismatic grooves of the sight glass so that bright indication is achieved. In the liquid phase, the light is absorbed, resulting in a dark indication of the level.

In which areas can transparent sight glass level indicators be used?

They are the most suitable gauges for steam application above 35 bar, where mica shields have to be used to protect the sight glasses from corrosion by the steam boiler water. They can also be utilised in a great number of other applications,in particular for observing interface layers or liquid colour. A backlight illuminator can be fitted to the rear to improve visibility.


What are the benefits of sight glasses in level measurement?

  • Detection of liquid level with glass level gauges is almost independent from physical properties like refraction index, density, conductivity, colour
  • Direct visualisation of the medium
  • No power supply required
  • Specified in accordance with several standards and customer standards
  • Simple and well-known technology
  • Robust design
  • Extremely low certification efforts