测定过程包括缓慢渐进地冷却精油，观察精油从液态到固态时的温度变化。测定冰点的装置由一个容量约为500毫升的宽口容器组成，容器上装有一个钻孔软木塞或橡胶塞，插入一根壁厚的试管。另一个较小的试管通过另一个钻孔软木塞或橡胶塞安装到坚固的壁试管中。在较小的试管中插入温度计。

The determination consists in slow and progressive cooling of the essential oil and observation of the variations in temperature as the oil passes from the liquid to the solid state. The apparatur for determination of freezing point consists of a wide-mouthed container of about 500 ml capacity, provided with a bored cork or rubber stopper into which a stout-walled test tube is inserted. Another smaller test tube is fitted into the stout-walled test tube by means of another bored cork or rubber stopper. Into the smaller test tube a thermometer is inserted.