沸点测定器(ebullioscope) 是一种用于测定液体沸点的工具。依据沸点升高原理，可用于确定混合物的酒精浓度和非挥发性溶质的分子质量。这一过程被称为沸点升高测定法(ebullioscopy）。

An ebullioscope (from the Latin ēbullīre (to boil) + -scope) is an instrument for measuring the boiling point of a liquid. This can be used for determining the alcoholic strength of a mixture, or for determining the molecular weight of a non-volatile solute based on the boiling-point elevation. The procedure is known as ebullioscopy.