Thermometer

A thermometer is a device used to measure temperature. It consists of a bulb filled with a liquid (usually mercury or colored alcohol) that expands and contracts with temperature changes, and a calibrated scale to measure the temperature.

Types of Thermometers

There are several types of thermometers, including:

• Mercury Thermometer: Uses mercury to measure temperature.
• Digital Thermometer: Displays temperature readings digitally.
• Infrared Thermometer: Measures temperature from a distance using infrared technology.
• Thermocouple Thermometer: Uses two different metals to measure temperature changes.

How Thermometers Work

When the temperature increases, the liquid in the bulb expands, causing it to rise in the calibrated tube. When the temperature decreases, the liquid contracts, causing it to fall in the tube. The scale is marked with units such as degrees Celsius or Fahrenheit to indicate the temperature.

Using a Thermometer

To use a thermometer, the bulb is placed in the substance or environment whose temperature is to be measured. After a few minutes, the reading can be obtained from the scale.

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 is the purpose of the calibrated scale on a thermometer?