The reflex level gauge is used to see the water level in the boiler drum. The working principle is based on the light separator & retraction laws.When in operation the chamber is filled with water in lower zone & vapors or gases in the upper zone. The liquid level is distinguished by the different brightness of the glass in liquid & in vapor zone. The liquid level (water) in the chamber will be seen blacky where as the vapor region will reflect silvery in color and then level can be distinguished. Learn More