Relates to C6 to C13 alcohols. The principle consists in distillation of a test portion, under carefull defined conditions. For measurement of distillation intervals not greater than 5 °C, the thermometer hsall be graduated at intervals of 0,2 °C; for intervals greater than 5 °C, the thermometer shall be graduated at intervals of 0,5 °C. Adjusting the rate of heating so that the first drop of distillate falls from the end of the condenser after 15 to 20 min. ISO 1843/7 cancels and replaces ISO Recommendation R 1845-1970, of which it constitutes a technical revision.