The UGS color quartz tube level gauge (hereinafter referred to as the color level gauge) is developed using domestic and foreign technology. It utilizes the principle of natural light refraction and reflection in liquids, and with the help of red and green sheets, the liquid phase is displayed in green and the gas phase is displayed in red during measurement. Due to the large contrast in liquid and gas phase display and clear indications, it is more advantageous for long-distance operation and night patrols. If equipped with LED light source, the display will be clearer. Therefore, it is widely used in various transparent liquid containers and boilers in industries such as petroleum, chemical, power, and metallurgy, such as water, gasoline, liquefied gas, liquid ammonia, propane, propylene, aromatics, acids, and other oil products and chemical raw materials for liquid level measurement. For interface measurements of two different media densities, a three sided quartz tube level gauge can be used. The three sided quartz tube liquid level gauge is designed based on the principle of buoyancy and specific gravity difference. The small float in the quartz tube is suspended at the boundary between the two media. Due to the black color of the float, the liquid in the upper and lower parts has different colors, so it displays prominently.