The working principle of the float is based on Archimedes’ principle of buoyancy. It achieves functions such as liquid level measurement and object retrieval by adjusting the balance between buoyancy and gravity，The specific mechanisms vary depending on the application scenarios.
The working principle of the liquid level measurement float
- Core principle : when part of the float is immersed in the liquid, the buoyant force it experiences is directly proportional to the height of the liquid level (float = liquid discharge F float =ρ liquid gV discharge). The change in liquid level causes the volume of the float submerged to change, thereby triggering a change in buoyancy.
- Force-signal conversion :
- Mechanical displacement : the resultant force of buoyancy and self-weight is converted into linear displacement through a spring or into angular displacement through a torque tube.
- Signal output : The magnetic coupling device (such as hall sensor /LVDT) converts the displacement into a 4~20mA electrical signal output.
- Compensation design : Some high-precision instruments adopt temperature compensation technology to reduce the influence of liquid density changes on the measurement results.
The working principle of the engineering floating device
- Buoyancy support structure：
- The sealed cavity float generates buoyancy by displacing water, and the buoyancy of a single float can reach several tons.
- Polymer material floats have the characteristics of impact resistance and corrosion resistance, making them suitable for long-term water operations.
- Salvage shipwreck application ：
- Key step : Fix the water-filled floating tubes on both sides of the sunken ship, inject air to drain water and reduce the total weight. When the buoyancy (float F float) is greater than the total gravity (total G total), the ship will rise.
- Mechanical equilibrium : after drainage, the gravity of the float decreases by approximately 90% (based on a water density of 1g/cm³), significantly enhancing the net buoyancy.