infrared radiation既問題

A good radiator of heat is also a good absorber of heat.

Because black surface object, when heated, will emit radiation of all possible wavelengths (The black-body radiation principle).

A black surface thus absorbs radiation of all wavelengths, including visible and infrared radiation.

The temperature so recorded by the thermometer is called the [Radiation Temperature], it is used to indicate the radiant energy emitted by the surrounding environment.