In liquid thermometers

Liquid thermometers are based on the thermal expansion of liquids.

In these thermometers some liquid is used as thermometric substance.

Liquid thermometers operate on the principle of thermal expansion, where liquids expand or contract in response to temperature changes. These thermometers utilize a liquid as the thermometric substance, which means the liquid is responsible for indicating the temperature.

When the temperature increases, the liquid inside the thermometer absorbs heat and expands. Conversely, when the temperature decreases, the liquid loses heat and contracts. This change in volume is visible through a calibrated scale marked on the thermometer, enabling accurate temperature readings.

Commonly used liquids in such thermometers include mercury and alcohol. Mercury is preferred for its high boiling point and consistent expansion rate, making it suitable for high-temperature measurements. Alcohol, on the other hand, is dyed for visibility and is often used for low-temperature measurements because it has a lower freezing point than mercury.

Liquid thermometers are widely used in various applications, including household, medical, and industrial settings, due to their simplicity, reliability, and ease of use. However, their accuracy depends on the thermal properties of the liquid and the precision of the scale.