Float Level Gauge is a liquid level measuring instrument which works based on the principle of constant buoyancy in buoyancy (Archimedes theorem).In the gravity field, the vertical upward force on the object in the fluid due to the density difference with the surrounding fluid is buoyancy.
In a liquid, an object whose overall density is lower than the liquid density will eventually float on the liquid surface. This object can be called a float. Under constant conditions, the buoyancy of the float is constant (constant buoyancy).
When the float is subjected to an upward force less than its own weight or a downward force less than the weight of the liquid equivalent to its own volume, the characteristic that the float will eventually float on the liquid surface will not be changed.
In the steady state, the buoyancy of the float is constant.
When the position of the liquid surface changes vertically, the vertical position of the float will change synchronously with the position of the liquid surface under the action of constant buoyancy.
The float level gauge is a device that displays the vertical position of the float in the form that people can read directly through various mechanical, electromagnetic, optical and other physical means.
