Understanding Liquid Thermometers: The Role of Thin Glass

Thermometers containing liquids have a very thin, hollow glass tube to easily record temperature readings. There are numbers based on a temperature scale that are along side of the tube to measure fluctuations in temperature.

Liquid Thermometers

• Liquid thermometers are the most common type in use today; they use mercury, lead, or alcohol (such as methanol) to register changes in temperatures. Thermometers are normally calibrated to measure temperatures ranging from 32 to 42 degrees Celsius.

Facts

• The liquid in the thermometer expands as the temperature increase. Since the liquid has no place to go but up or down inside the glass tube, the length of the liquid will display the temperature readings.

Theories

• Liquid thermometers are made with thin glass to be able to calibrate constant temperature readings of the apparent thermal expansion of the liquid. Thin glass tubes are known to be sensitive to changes in temperatures and are capable of responding well to liquids -- resulting in accurate readings.