How Performance Metrics are Used

Light Output (Lumens)

The unit of lumens measures light output, which measures the perceived power of visible light emitted from a light source. However, lumens do not adequately characterize the performance of any light source and must be weighed against other factors, such as peak beam intensity, to represent the performance of a product.

Runtime (Hours)

FL-1 dictates that runtime be measured to 10% of a product’s original light output. This is due to the characteristic of some lights that allow LEDs to remain emitting for hundreds of hours, though the vast majority of this time, the LEDs are no longer emitting a useful amount of light. A 300-lumen light will have its runtime considered complete if its total light output drops below 30 lumens.

Peak Beam Intensity (Candela)

The unit of candela measures peak beam intensity. Peak beam intensity (PBI) characterizes the light intensity on a target, measured at the brightest single point. FL-1 Standards require all peak beam intensity to be normalized to candela, which considers measurement distance. The unit candela is equal to a measured lux value multiplied by the square of measurement distance in meters. Lux alone cannot characterize the intensity of light, as lux can increase as the distance from the target decrease. Generally speaking, highly focused lights will have higher peak beam intensity values, and lower focused lights, such as flood lights, will have lower peak beam intensity values. 

Impact Resistance (Meters)

Simply put, this is a product’s drop rating. Six drops from a defined height onto concrete are performed, hitting all six cubic faces of the product from the same height: top, bottom, left, right, front, and back. Any external fracture or internal break that inhibits the normal function of the light, including its ability to retain its IP rating, would be deemed a failure. 

Beam Distance (meters)

Beam distance, measured in meters, is calculated from candela and is meant to define the distance at which a light source is equal to a full moon on a clear night (0.25 lux).  The measured value of peak beam intensity is used in the following formula to define beam distance.

Ingress Protection (IPX Rating

Qualifies a product’s ability to remain impervious to dust or water under certain conditions.  IP testing is performed on a product after impact resistance (drop) testing.  The IP Rating chart defines the product rating using a number representing each category.  Typically, products will be rated IPX#, with an X to designate it has not been tested or certified to dust and a # to define its water ingress protection level.   Dust ratings are typically not required, except for in specific intrinsically safe applications, in which case the dust rating would be marked on the product and displayed on the certificate.