Define Lumen

 Define Lumen

A lumen (lm) is a unit of measurement used to quantify the amount of light emitted by a light source. It is a measure of the total amount of visible light that a light source emits in all directions, as perceived by the human eye.

To understand the concept of lumens, it's important to first define luminous flux. Luminous flux is the total amount of visible light emitted by a light source per second, and it is measured in lumens (lm).

Lumens are used to compare the brightness of different light sources. For example, a light bulb with a higher lumen output will produce more visible light and appear brighter than a light bulb with a lower lumen output.

It's worth noting that lumens do not take into account the direction of the light, but rather the total amount of light emitted in all directions. In contrast, other units of measurement like candela and lux are used to measure the intensity and brightness of light in specific directions.

In summary, lumens are a unit of measurement used to quantify the total amount of visible light emitted by a light source in all directions. They are used to compare the brightness of different light sources, and are measured in lumens (lm).