What is the primary function of a thermometer?

The primary function of a thermometer is to measure temperature. This device is specifically designed to gauge the degree of heat present in an object or environment, which is essential in various fields, including healthcare, cooking, and scientific research. Temperature measurement is critical in healthcare for monitoring patients' body temperature to identify fevers or hypothermia, which can indicate underlying health issues.

While other instruments are used to measure humidity, pressure, and volume, these functions are outside the scope of a thermometer's purpose. Each measuring tool is specialized for specific physical properties, and a thermometer is exclusively focused on temperature measurement.