What is a siphon primarily used for in operation?

A siphon operates on the principle of gravity and atmospheric pressure, allowing liquid to flow from a higher elevation to a lower elevation without the need for a pump. The primary purpose of a siphon is to move fluids through a pipeline that has differing elevations, which creates the necessary pressure difference to facilitate the flow.

In essence, once a siphon is filled and the flow is initiated, the liquid continues to flow due to gravity, especially when the outlet is lower than the inlet. This is particularly useful in various applications such as draining tanks, transferring liquids between containers at different heights, and managing fluid levels in systems like aqueducts or irrigation.

The other options describe methods or devices that do not directly relate to the core function of a siphon. For instance, a pump specifically refers to a mechanical device that raises liquids, which diverges from the passive operation of a siphon. Likewise, collecting ambient air and measuring atmospheric conditions pertain to meteorological instruments rather than fluid transfer methods.