acidometer noun2 •A hydrometer, especially one that is used to measure the strength of an acid.If the liquid becomes denser, i.e., of greater specific gravity, the acidometer rises, so that more of the tube and its scale is exposed above the liquid, and vice versa. — 1890 •Any of various other devices used to measure acidity, either chemical or electronic.We think the acidometer a very dangerous instrument in the hands of the inexperienced, as the solution of ammonia is subject to the influence of air so much. — 1870 formsacidometers
