How do you measure temperature changes in a system?

You measure temperature changes in a system using a thermometer or a temperature sensor.

To measure temperature changes accurately, you can use different types of thermometers, such as liquid-in-glass thermometers, digital thermometers, or thermocouples. A liquid-in-glass thermometer contains a liquid, usually mercury or alcohol, that expands and contracts with temperature changes. You read the temperature by looking at the level of the liquid against a calibrated scale.

Digital thermometers use electronic sensors to measure temperature. These sensors, often made from materials like thermistors or resistance temperature detectors (RTDs), change their electrical resistance with temperature. The thermometer's circuitry converts this change in resistance into a temperature reading, which is displayed on a digital screen.

Thermocouples are another type of temperature sensor, commonly used in scientific and industrial applications. They consist of two different metals joined at one end. When the junction of the two metals is heated or cooled, it produces a voltage that can be measured and converted into a temperature reading.

When measuring temperature changes, it's important to ensure that the thermometer or sensor is in good contact with the system you're studying. For example, if you're measuring the temperature of a liquid, make sure the thermometer is fully submerged. If you're measuring the temperature of a solid object, ensure the sensor is firmly attached to the surface.

Additionally, consider the response time of your thermometer or sensor. Some devices, like digital thermometers, provide almost instant readings, while others, like liquid-in-glass thermometers, may take a few moments to stabilise. Always wait for the reading to settle before recording the temperature to ensure accuracy.