Thermometer

A thermometer is a device used to measure temperature. It consists of a narrow, sealed glass tube with a bulb at one end that contains a liquid (usually mercury or colored alcohol) which expands and rises in the tube as the temperature increases.

Types of Thermometers

There are several types of thermometers:

• Mercury Thermometer: Uses mercury as the liquid and has a narrow temperature range.
• Digital Thermometer: Uses electronic sensors to measure temperature and provides a digital readout.
• Infrared Thermometer: Measures temperature from a distance using infrared technology.
• Bimetallic Strip Thermometer: Uses the expansion and contraction of two different metals to measure temperature changes.

How Thermometers Work

When the temperature increases, the particles of the liquid inside the thermometer gain kinetic energy and move faster, causing the liquid to expand and rise in the tube. This expansion is measured on a scale marked on the thermometer, providing a numerical value for the temperature.

Using a Thermometer

To use a thermometer, place the bulb end in the area whose temperature you want to measure. Wait for a few moments to allow the liquid to reach the temperature of the surroundings, then read the temperature from the scale.

Applications of Thermometers

Thermometers are used in various fields, including weather forecasting, medical applications, cooking, and industrial processes to monitor and control temperature.

Study Guide Questions

1. What is a thermometer and how does it work?
2. What are the different types of thermometers?
3. How is temperature measured using a thermometer?
4. What are the applications of thermometers?