Principle of hydrometer/sugar meter
The principle of the hydrometer is the same as that of the sugar meter. It measures the specific gravity of a specific solution by the height it floats in the solution. It measures the relative density, which is the density of the solution relative to water. The specific gravity of water is 1.000. At temperature (20°C), the density of a liquid is temperature dependent, so the reading of the hydrometer/brix meter should be corrected to the specific gravity at the standard temperature.
It's just that the units of the sugar meter and the hydrometer are different, but the units can be converted.
Accurate experimental conversion formula:
°P=(-668.962)+(1262.45*specific gravity)-776.43*(the second power of the specific gravity)+(182.94*the third power of the specific gravity)
Estimation formula:
Sugar content ≈【(specific gravity—1)*1000】/4
For example, the specific gravity of wort measured at 20°C is 1.048, and the exact conversion sugar content is 11.9 °P, which is approximately equal to 12 °P according to the estimation formula
