gas thermometer

A gas thermometer is a type of thermometer that uses gas as its thermometric substance. It measures temperature by observing changes in the pressure of a fixed amount of gas at constant volume, or changes in the volume of a fixed amount of gas at constant pressure.1

Thermometers, in general, are instruments used to measure temperature, a crucial factor in various fields like manufacturing, scientific research, and medicine. The invention of the thermometer is often attributed to Galileo Galilei, whose early instrument utilized the expansion and contraction of air to indicate temperature changes. Over time, these instruments evolved, with mercury and alcohol becoming common liquids, and standardized scales like Fahrenheit and Celsius being developed. Modern thermometers include digital and infrared types, utilizing electronic components like thermistors. Gas thermometers are particularly effective at very low temperatures.2