Maximum-Minimum Thermometer is a scientific instrument designed to measure and record the highest and lowest temperatures that occur during a specific period, typically over 24 hours. Unlike standard thermometers, which only show the current temperature, a maximum-minimum thermometer is used to capture the extreme temperature values, offering valuable information for meteorological and environmental monitoring.A typical maximum-minimum thermometer consists of a mercury or alcohol column inside a glass tube, with two distinct markers for maximum and minimum readings. There are two main types of maximum-minimum thermometers: liquid-in-glass thermometers and spirit (alcohol) thermometers, both employing a capillary tube mechanism.minimum marker is often a small, movable indicator that records the lowest temperature during the period. In liquid-in-glass thermometers, the minimum marker may be a small pin or ball that moves freely within the liquid, which is displaced as the temperature drops.