Temperature and It's Measurement Class 6 Notes

Temperature and It’s Measurement: Temperature tells us how hot or cold something is. It shows the amount of heat present in an object. We use different instruments to measure temperature, and the most common one is a thermometer. The main units of temperature are Celsius (°C), Fahrenheit (°F), and Kelvin (K).

In daily life, Celsius is mostly used, while scientists often use Kelvin. Temperature can be measured in solids, liquids, and gases. For example, we use a clinical thermometer to measure body temperature. Accurate temperature measurement is important in cooking, weather forecasting, medicine, and scientific experiments. It helps us understand and control heat around us.

How To Measure Temperature Using a Thermometer?

A thermometer is a device that measures the temperature of body. Thermometers have a long, narrow glass tube. There is a small bulb at one end that contains a liquid, usually mercury or alcohol.

When the bulb touches a hot object, the liquid inside expands (grows) and rises in the tube. When it touches a cold object, the liquid contracts (shrinks) and moves down. We read the temperature by looking at the mark where the liquid column stops.

Types of Thermometers

There are two main types of thermometers used, known as Clinical thermometers and Laboratory thermometers.

Clinical Thermometer

• This thermometer is used to measure human body temperature.
• Clinical Thermometer range is 35°C to 42°C and or from 94°F to 108°F.
• It has a kink (a small bend) near the bulb. This kink stops the mercury from falling back quickly when the thermometer is taken out of the mouth. This allows us to read the correct temperature

Laboratory Thermometer

• This thermometer is used to measure the temperature of things like water, solutions, or chemicals in a lab.
• Its range is much wider, usually from 10˚C to 110˚C.
• It does not have a kink. The reading must be taken while the thermometer is still dipped in the substance.

Units of Thermometer

A thermometer measures temperature using specific units. The three common units are Celsius (°C), Fahrenheit (°F), and Kelvin (K). Celsius is widely used in most countries, Fahrenheit is common in the United States, and Kelvin is used in scientific research. These units help compare and record temperature changes accurately in daily life and experiments.

Important Tips for Reading Thermometer

Students should consider the important tips to know on reading a thermometer for measurement.

• Hold the thermometer at eye level for an accurate reading.
• Ensure the thermometer is clean before and after use.
• Wait for the required time before checking the reading.
• Read the temperature from the correct scale (°C or °F).
• Avoid touching the bulb or sensor while measuring.
• Note the reading immediately after use.