An ebulliometer is designed to accurately measure the boiling point

Boiling point

The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid....

 of liquids by measuring the temperature of the vapor-liquid equilibrium either isobarically or isothermally.

The primary components in a Swietoslawski ebulliometer, which operates isobarically, are: the boiler, the Cottrell

Frederick Gardner Cottrell

Frederick Gardner Cottrell was an American physical chemist and inventor. A native of Oakland, California, his immense curiosity gained him notice as a prodigious reader. But his achievements were also an ambitious response to economic necessity...

 pumps, the thermowell

Thermowell

Thermowells are used to protect temperature sensors used to monitor industrial processes while permitting accurate measurement. They are typically installed in piping systems and subject to both hydrostatic and aerodynamic forces...

, and the condenser. Such an ebulliometer can be used for extremely accurate measurements of boiling temperature, molecular weights, mutual solubilities, and solvent purities by using a resistance temperature device (RTD) to measure the near-equilibrium conditions of the thermowell.

The ebulliometer is frequently used for measuring the alcohol content of dry wines. See also Sweetness of wine

Sweetness of wine

The subjective sweetness of a wine is determined by the interaction of several factors, including the amount of sugar in the wine to be sure, but also the relative levels of alcohol, acids, and tannins. Briefly: sugars and alcohol enhance a wine's sweetness; acids and bitter tannins counteract it...

 and Oechsle scale.