noun
Usage: usually capitalized B
Etymology: after Antoine Baumé
: either of two arbitrary hydrometer scales, one for liquids lighter than water and the other for liquids heavier than water, that indicate specific gravity in degrees, the intervals between the degree graduations being of equal length, readings on the scale being approximately reducible to specific gravities by the following formulas given by the United States Bureau of Standards ( n in each case being the reading on the Baumé scale): (a) for liquids heavier than water, specific gravity = 145 ÷ (145 - n ) at 60° F; (b) for liquids lighter than water, specific gravity = 140 ÷ (130 + n ) at 60° F