The quartz tube level gauge is a direct-reading instrument that utilizes optical principles and the communicating vessel principle to display liquid level positions. It can be widely used in medium and low-pressure boiler steam drums and storage tanks. According to the display method, it can be divided into single-color and dual-color types: the single-color level gauge directly displays the natural color of the medium; the dual-color level gauge shows green for the liquid phase and red for the vapor phase, with the red-green interface indicating the liquid level position. Additionally, this type of level gauge offers advantages such as simple structure, easy maintenance, and high safety and reliability.

 The SF304 and SF304A quartz tube level gauges are available with two lighting methods: quartz lamp tube and LED cold light source illumination.