Which instrument is used to measure temperature?

The instrument used to measure temperature is the thermometer. It is designed specifically to quantify how hot or cold a substance is, providing readings in various units such as degrees Celsius or Fahrenheit. This device functions based on the principle that materials expand when heated and contract when cooled, often utilizing liquids such as mercury or alcohol, or more modern electronic components for precise measurements.

In contrast, a barometer is used for measuring atmospheric pressure, which plays a crucial role in weather forecasting but does not provide temperature readings. An anemometer measures wind speed, essential for understanding weather patterns and dynamics but not for temperature assessment. A hygrometer measures humidity levels in the air, providing insights into moisture content but not temperature. Thus, the thermometer is the correct choice for measuring temperature.