Thermometer

A thermometer is a device used to measure temperature. It consists of a long, narrow, uniform glass tube with a bulb at one end that contains a liquid (such as mercury or alcohol) which expands and contracts with changes in temperature.

Types of Thermometers

1. Mercury Thermometer: This type of thermometer uses mercury as the liquid inside the bulb. It is commonly used in various applications due to its accuracy.
2. Digital Thermometer: These thermometers use electronic sensors to measure temperature and display the reading on a digital screen.
3. Infrared Thermometer: An infrared thermometer uses a laser to measure temperature from a distance without making any physical contact with the object being measured.

How Thermometers Work

When the temperature increases, the liquid inside the bulb expands and rises up the tube, and when the temperature decreases, the liquid contracts and moves down the tube. The temperature is read by observing the level of the liquid in relation to the markings on the thermometer's scale.

Temperature Scales

There are different temperature scales used around the world:

• Celsius (°C): The Celsius scale is commonly used in scientific and everyday applications. Water freezes at 0°C and boils at 100°C at standard atmospheric pressure.
• Fahrenheit (°F): The Fahrenheit scale is used mainly in the United States. Water freezes at 32°F and boils at 212°F at standard atmospheric pressure.
• Kelvin (K): The Kelvin scale is used in scientific research and is based on absolute zero, the theoretical lowest possible temperature. Absolute zero is 0 Kelvin.

Applications of Thermometers

Thermometers are used in various fields and applications including weather monitoring, medical diagnosis, food safety, cooking, and industrial processes. They are essential for ensuring the proper functioning of equipment and maintaining optimal conditions for various processes.

Study Guide

Here are some key points to remember about thermometers:

1. Understand the different types of thermometers and their uses.
2. Be familiar with how thermometers work and the principles behind temperature measurement.
3. Learn about the various temperature scales and their applications.
4. Explore the real-world applications of thermometers in different fields.

Understanding the concept of thermometers and temperature measurement is crucial in many scientific and practical applications. Take time to review and practice using thermometers to measure temperature accurately and effectively.