Parameters of industrial light sources; Lumen

In industrial light sources, lumen (symbol: lm) is the unit used to measure the total luminous flux of a light source. It represents the sum of visible light energy emitted by the light source in all directions and directly reflects the overall luminous brightness of the light source.

Simply put, a higher lumen value means the light source emits a greater "total amount of light", and it usually provides a larger illuminated range or higher brightness of illuminated objects under the same environment. For example:

- If an LED light source used for industrial inspection is labeled with a luminous flux of 5000 lm, its overall light output will be much higher than that of a same-type light source with 1000 lm. It is more suitable for inspection scenarios requiring high-brightness illumination (such as surface defect inspection of precision parts).

- It is different from "illuminance (lux)": lumens describe "how much light a light source emits", while lux describes "how much light is received on the surface of an illuminated object". The two need to be correlated by combining factors such as irradiation distance and angle.