What device measures the specific gravity of liquid?

What device measures the specific gravity of liquid?

• A. Hydrometer
• B. Barometer
• C. Psychrometer
• D. Manometer

Answer: (A)

The hydrometer is specifically designed to measure the specific gravity of liquids. Specific gravity is a dimensionless quantity that compares the density of a substance to the density of a reference substance, typically water. A hydrometer operates on the principle of buoyancy; when it is placed in a liquid, it displaces a volume of that liquid. The level to which the hydrometer sinks indicates the liquid's density, from which the specific gravity can be calculated. In other contexts, a barometer measures atmospheric pressure, a psychrometer assesses humidity by comparing temperatures from wet and dry bulbs, and a manometer measures gas or liquid pressure. None of these devices are designed to measure the specific gravity of a liquid, which clearly distinguishes the hydrometer's unique function.

The hydrometer is specifically designed to measure the specific gravity of liquids. Specific gravity is a dimensionless quantity that compares the density of a substance to the density of a reference substance, typically water. A hydrometer operates on the principle of buoyancy; when it is placed in a liquid, it displaces a volume of that liquid. The level to which the hydrometer sinks indicates the liquid's density, from which the specific gravity can be calculated.

In other contexts, a barometer measures atmospheric pressure, a psychrometer assesses humidity by comparing temperatures from wet and dry bulbs, and a manometer measures gas or liquid pressure. None of these devices are designed to measure the specific gravity of a liquid, which clearly distinguishes the hydrometer's unique function.