Units of luminous energy

The unit of luminous energy is the "lumen second" (lm·s). Luminous energy refers to the total amount of visible light emitted by a light source, taking into account the sensitivity of the human eye to different wavelengths of light. It is derived from the measurement of luminous flux (in lumens) over a period of time (in seconds).

The term "lumen second" refers to a unit of measurement used in photometry, which is the science of measuring visible light. Specifically, the lumen (lm) is the SI unit of luminous flux, a measure of the perceived power of light. A "lumen second" would represent a quantity of light emitted over a time period of one second. In practical terms, if a light source emits one lumen of light continuously for one second, it would deliver one lumen second of luminous flux.