Abstract
In order to establish a standard in the alcoholometry in Japan, a new alcoholometric specific gravity table is compiled at the National Research Laboratory of Metrology. The compiled tables give specific gravities of five places of decimals corresponding to every integral's percentage by weight in alcohol-water mixture at intervals of 5°C in temperature range from -20°C to 30°C.
The table has the following characteristics in the method of its compilation:
1) The specific gravity of pure ethyl-alcohol is determined by extrapolating the relation between specific gravities and concentrations of nearly pure ethyl-alcohol, whose water contents are measured by the Karl-Fischer method.
2) The relation between alcohol concentration and specific gravity of alcohol-water mixture is expressed by a polynomial of 11 degrees for 0, 5, 10, 15, 20, 25 and 30°C, by a polynomial of 7 degrees for -5 and -10°C and by a polynomial of 6 degrees for -15 and -20°C; the coefficients in the polynomials being determined statistically from many measurement values on concentration and specific gravity of alcohol-water mixtures.
