The Baumé scale is a measure of a solution’s specific gravity, not its concentration, you’ll have to convert degrees Baumé to a specific gravity, and then use the specific gravity to look up the concentration of your solution from a table in a handbook. For example, the CRC handbook has tables that relate specific gravities to concentrations of various liquids.
The French chemist Antoine Baumé devised the scale for marking hydrometers. For liquids that are heavier than water, 0°Bé marks the water level of the hydrometer placed in pure water, and 15°Bé corresponds to the water level when the scale is placed in a solution that is 15% NaCl by mass. For liquids that are lighter than water, 10°Bé marks the level for pure water and 0°Bé corresponds to a solution that is 10% NaCl by mass.
At 60°F, specific gravity can be calculated from degrees Baumé using the following formulas:
|liquids lighter than water:||sp. gr. = 140/(°Bé + 130)|
|liquids heavier than water:||sp. gr. = 145/(145 – °Bé)|
Note that a “new” scale called the Gerlach scale uses 146.78 in the heavier-than-water equation rather than 145.