What is the primary function of floats in liquid level sensing?

The primary function of floats in liquid level sensing is to indicate level based on buoyancy. When a float is placed in a liquid, it rises and falls with the liquid's surface level due to its buoyancy. This movement of the float can be translated into a measurement of the liquid level, allowing operators to monitor the volume of liquid in a tank or containment area accurately. The float’s position can be used mechanically or electronically to trigger alarms, control pumps, or provide continuous readings of liquid levels.

Other options do not pertain to the function of floats in level detection. Measuring viscosity involves analyzing the thickness or resistance of a fluid to flow, which is unrelated to how floats operate. Controlling temperature generally requires different types of sensors and equipment designed specifically for thermal management, rather than buoyancy devices. Detecting flow rate involves measuring the speed of liquid moving through a pipe or channel, which is distinctly different from level measurement and does not utilize the buoyancy mechanism of a float.