What is an Ebulliometer?

An ebulliometer is a measuring device that is designed to evaluate the boiling point of different types of liquids. A common use of this device is in the wine industry, as a means of separating various elements into gas and measuring the alcohol content of a specific vintage or batch of wine. Alcohol boils at a lower temperature than water does, and by measuring the boiling point of a batch of wine or other liquid, an ebulliometer can determine that batch's alcohol level. Ebulliometers are used by many wineries to maintain a consistent alcohol level in all varieties of the wine that they produce.

The point of measurement that is monitored with the use of an ebulliometer is the balance of vapor-liquid equality within the wine. There are two basic types of these devices that are used: isobaric and isothermic. A Swietoslawski ebulliometer relies on the isobaric method. This form of ebulliometer contains a boiler, Cotterell pumps, a condenser and a thermowell.

The measurements obtained with this type of ebulliometer are considered to be very exact. An isobaric ebulliometer provides measurements of such factors as the exact temperature needed to reach a boiling point, solvent purities within the properties of the sample and the molecular weight of the substance. The use of a resistance temperature device (RTD) helps create the accurate readings on the vapor-liquid equilibrium of the wine, which is one factor that makes the isobaric approach the most accurate reading possible with this type of device.

An isothermal ebulliometer contains similar components as the isobaric type, but it usually involves the presence of a stirring mechanism that is operated by a small pump. The stirring takes place during the process of boiling the mixture and is thought to increase the chances for a more accurate reading of gases within the mixture, such as methanol. Although not as prominently in use as the isobaric type, this method is preferred by many wineries for maintaining the quality of their wines.

Ebulliometers have enjoyed a long association with the wine industry. For many years, these devices were considered the only viable method of obtaining accurate readings on the alcohol content of wine samples. More recently, the gas chromatograph has gained a great deal of acceptance with many winery facilities. Still, the use of ebulliometers within the industry has remained common, and these device have a solid reputation for producing accurate measurements.