Halogen

Light measuring devices called lux meters can measure with high precision in a wide measuring range. But when it comes to LEDs things get a little more complicated. Different brands and models of lux meters may take different measurements at the same point.

The most common causes of LED failures are the use of poor quality LEDs, improper soldering of the LEDs, exposure to high temperatures, insufficient heatsink design, no current limitation in the power supply circuit, and problems with the battery.