In branches of physics other than radiometry, electromagnetic energy is referred to using E or W. The term is used particularly when electromagnetic radiation is emitted by a source into the surrounding environment.
Di cabang-cabang fisika selain radiometri, energi elektromagnetik menggunakan E atau W. Istilah ini digunakan terutama bila radiasi elektromagnetik dipancarkan oleh suatu sumber ke lingkungan sekitarnya.