Final answer:
There are three common types of thermometers: alcohol, which uses a liquid that expands in a tube; liquid crystal, which changes color at specific temperatures; and infrared radiation, providing a non-contact method of measuring temperature. They use Fahrenheit, Celsius, and Kelvin scales for temperature measurements.
Step-by-step explanation:
Thermometers are instruments used for measuring temperature through various methods, depending on the type and intended use. The three main types of thermometers are alcohol thermometers, liquid crystal thermometers, and infrared radiation thermometers (also known as pyrometers).
Alcohol thermometers contain a liquid, usually colored alcohol, in a glass tube that expands and contracts with temperature changes, moving up and down to indicate the temperature. Liquid crystal thermometers consist of heat-sensitive liquid crystals that change color based on the temperature. When exposed to a specific temperature, each crystal changes to a distinct color, providing a temperature reading. Infrared radiation thermometers measure the infrared radiation emitted by an object, which varies with temperature, and provides a quick and non-contact way to measure temperature—ideal for checking body temperature in the ear canal or measuring the heat of an object from a distance.
Thermometers correspond to different temperature scales: Fahrenheit (°F), Celsius (°C), and Kelvin (K), with reference points like the freezing and boiling points of water at standard atmospheric pressure to calibrate these scales.