liquid thermometer

measurement device

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Last updated

June 30, 2026

Quick Summary

A liquid thermometer is an instrument used to measure temperature. It typically consists of a glass tube containing a liquid, such as mercury or alcohol, which expands or contracts with changes in temperature. This expansion or contraction causes the liquid level in the tube to rise or fall, indicating the temperature on a calibrated scale.

While early thermometers, like Galileo Galilei's, used air, later versions perfected the use of liquids. Daniel Gabriel Fahrenheit and Anders Celsius developed standardized temperature scales that are still in use today. Liquid thermometers were once common due to their simplicity and affordability, but they have largely been replaced by electronic digital thermometers, which are more accurate and do not contain toxic mercury.1

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thermometer
Liquid thermometers were once the most common type in use. They were simple, inexpensive, long-lasting, and able to measure a wide temperature span. The liquid was almost always mercury or coloured alcohol, sealed in a glass tube with a gas like nitrogen or argon making…
Read More
Liquid thermometers were once the most common type in use. They were simple, inexpensive, long-lasting, and able to measure a wide temperature span. The liquid was almost always mercury or coloured alcohol, sealed in a glass tube with a gas like nitrogen or argon making…
Read More