What is max-min thermometer?

A max-min thermometer is a type of thermometer that measures and displays the highest and lowest temperature readings over a certain period of time. The thermometer is typically made up of two separate columns of liquid, one containing mercury or alcohol, which expands as the temperature rises and contracts as the temperature drops.

The first column indicates the highest temperature reached since the thermometer was last reset, while the second column indicates the lowest temperature reached. Max-min thermometers have the advantage of allowing people to easily monitor changes in temperature conditions over a period of time. They are commonly used in greenhouses, weather monitoring stations, and other environments where it is important to keep track of temperature fluctuations.