Hydrometer vs. Areometer

An instrument used to determine specific gravity, especially a sealed, graduated tube, weighted at one end, that sinks in a fluid to a depth used as a measure of the fluid's specific gravity.

Any device used to measure the specific gravity of liquids or the density of solids.

An instrument that floats in a liquid and measures its specific gravity on a scale.

An instrument for measuring the specific gravity of fluids; a form hydrometer.

An instrument for determining the specific gravities of liquids, and thence the strength spirituous liquors, saline solutions, etc.

An instrument, variously constructed, used for measuring the velocity or discharge of water, as in rivers, from reservoirs, etc., and called by various specific names according to its construction or use, as tachometer, rheometer, hydrometer, pendulum, etc.; a current gauge.

A measuring instrument for determining the specific gravity of a liquid or solid