Understanding LED Testing

In order to determine how long LEDs will last or how a luminaire will survive in wet weather, there many tests they go through. Here is a general list of the types of tests that LED chips, lamps and luminaires can go through.

How are LEDs tested?

IES LM-79-08
Provide procedures for reproducible measurements of photometry, color and electrical characteristics of SSL products.

What can be tested with this standard?

Total luminous flux
Luminous intensity
Zonal lumen summation
CCT (Correlated Color Temperature)
CRI (Color Rendering Index)
Chromaticity Coordinates (x,y and u’,v’)
Spatial uniformity of color

IES LM-80-08
Provide methods of the measurement of lumen maintenance of LED packages, arrays and modules.

IES TM-21-11
Provide a calculation tool to interpret the data collected from LM-80 testing; to provide users with lumen maintenance life (e.g., L70) projection, or to predict estimated lumen output values at a given time duration; to interpolate lumen maintenance behaviors for the in-situ temperature (different from testing temperature)