Portable digital density meters calculate alcohol content at 20 °C from density and temperature.
Compact and robust, they are ideal for quick measurements in the field — in cellars, tank rooms, or at the base of transport containers.
This guide will help you achieve reliable results, avoid common errors, and get the most out of your equipment.
The official method for determining the alcohol content of a spirit requires prior distillation to eliminate residues that could distort the density measurement. However, distillation does not completely eliminate all volatile compounds other than ethanol.
What about measurements made with automatic or semi-automatic devices, very selective for the analysis of ethanol, such as near infrared analyzers?
The Practical Guide to Alcoholometry includes charts, white pages (Table VII b) and yellow pages (Table XI bb), used to determine the alcohol level at 20°C and calculate the volume of pure alcohol.
This article presents the principle of use of these charts and the differences between these 2 tables. It shows that the volume of pure alcohol calculated with the yellow pages is more approximate. It also explains how to convert at 20°C, a volume measurement when the alcohol level measurement is obtained directly at 20°C.