Nestetermometreissä

Nestetermometreissä, often translated as liquid-in-glass thermometers, are a type of thermometer that utilizes the thermal expansion of a liquid to measure temperature. The most common liquid used is mercury, though alcohol-based thermometers are also prevalent, particularly for lower temperature ranges. These thermometers consist of a glass tube sealed at one end, with a reservoir at the other end containing the liquid. A narrow capillary tube runs the length of the sealed stem, and a scale is marked alongside it.

When the temperature rises, the liquid in the reservoir expands and is forced up into the capillary tube. The height the liquid reaches on the marked scale directly corresponds to the measured temperature. Conversely, as the temperature falls, the liquid contracts and recedes down the capillary. The accuracy of a nestetermometri depends on factors such as the uniformity of the capillary bore, the purity of the liquid, and the precision of the etched scale. They are widely used in laboratories, households, and industrial settings due to their simplicity, cost-effectiveness, and reliability. However, mercury thermometers pose environmental and health risks due to mercury's toxicity, leading to a decline in their use in favor of digital or alcohol-based alternatives. Alcohol thermometers are often colored red or blue to make the liquid column more visible.