The Baume scale is a pair of hydrometer scales developed by French pharmacist Antoine Baumé in 1768 to measure density of various liquids. The unit of the Baumé scale has been notated variously as degrees Baume, Baumé, B°, Bé° and simply Baumé (the accent is not always present). One scale measures the density of liquids heavier than water and the other, liquids lighter than water. The Baumé of distilled water would be 0. Our ASTM Specification hydrometers are manufactured in strict accordance to specifications of ASTM (American Society for Testing and Materials) for accuracy and design.