The methods of standardization or calibration employed have much in common even in the cases that appear most diverse.
The joule (/ËdÊuËl/), symbol J, is a derived unit of energy in the International System of Units. It is equal to the energy transferred (or work done) to an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or NÂ·m).
In radiometry, radiant energy is the energy of electromagnetic radiation. The SI unit of radiant energy is the joule (J). The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time.