A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically...

The Pump-areometer was an early hydrometer (a variant of the syphon-hydrometer), credited to Floris Nollet. The principle is an inverted glass tube with...

convert the flow of air into electrical signals. Another instrument called areometer (from Ancient Greek ἀραιός -araiós "lightness" and μέτρον -métron "measure...

1718, Fahrenheit returned to Amsterdam and began selling barometers, areometers, and his mercury and alcohol-based thermometers commercially.: 8  By 1721...