Segment V2.6: Hydrometer

(Related to Textbook Section 2.11.1 - Archimedes' Principle)

The specific gravity of a liquid can be determined using Archimedes' principle.

A hydrometer is a glass bulb weighted on one end with a narrow stem at the other end. When placed in a liquid, such as water, it will float when the constant weight of the hydrometer is balanced by the buoyant force. Readings along the stem can be related to the specific gravity of the liquid. If the water is replaced with a heavier liquid (green salt water) the hydrometer will rise since a smaller displaced volume is required to balance the weight.