The magnetic float type liquid level gauge is installed on the extension pipe outside the tank, and the liquid level inside the tank can be clearly indicated by the flap indicator. A magnetic switch can also be installed on the outside of the bypass pipe as an electrical contact signal output, or a liquid level transmitter can be installed for long-distance liquid level signal transmission and liquid level control. This level gauge is a reliable safety instrument. The liquid level gauge works based on the principles of buoyancy and magnetic coupling. When the liquid level in the tested container rises or falls, the float in the main tube of the level gauge also rises or falls accordingly. The permanent magnetic steel inside the float is transmitted to the on-site indicator through magnetic coupling, driving the red and white flip columns to flip 180 °. The liquid level rises, and the flipping column changes from white to red; When the liquid level drops, the flipping column turns white, and the red and white boundary of the indicator is the actual height of the medium liquid level in the container, thus achieving liquid level indication.