Used to separate mixture of liquids by taking advantage of their different boiling points.
A barometer tube is a slender, sealed, and typically transparent tube used in barometers to measure atmospheric pressure. It is usually filled with a liquid, often mercury, but sometimes water or another fluid, which rises or falls within the tube in response to changes in atmospheric pressure. The height of the liquid column in the tube serves as an indicator of the current atmospheric pressure, with higher pressure causing the liquid to fall and lower pressure causing it to rise. This measurement helps in predicting weather changes and understanding atmospheric conditions.