UGS color quartz tube level gauge (hereinafter referred to as color level gauge) is developed by color technology at home and abroad. It is the use of natural light in the liquid folding, reflection principle, with the help of red, green, in the measurement, so that the liquid phase shows green, gas phase shows red. Because of the contrast of liquid and gas phase display, the indication is bright and clear, so it is more favorable for long-distance operation and night patrol. The display will be clearer if there is an LED light source. Therefore, it is widely used in petroleum, chemical, electric power, metallurgy and other industries of all kinds of transparent liquid containers and boilers, such as water, gasoline, liquefied gas, liquid ammonia, propane, propylene, aromatics, acids and other oil and chemical raw materials level measurement. At the same time, for the interface measurement of the density of two different media, the three-color interface quartz tube level meter can be used. Three-color interface quartz tube level meter is designed by using the principle of buoyancy and specific gravity difference. The small float in the quartz tube is suspended in the boundary part of two kinds of media. Because the float is black, the upper and lower part of the liquid color is different, so it shows eye-catching.