比ひ重じゅう計けいひじゅうけいMeanings1nounhydrometer; densimeterA scientific instrument for measuring the specific gravity or density of liquids. Technical term used in physics, chemistry, and industry.比ひ重じゅう計けいを使つかって液えき体たいの密みつ度どを測そく定ていした。We measured the density of the liquid using a hydrometer.