Hi Lee,

Frankly, I don't know the spectral output of the white LED and that's why I mentioned "if it matches". Thanks for the info on white LED. I learnt something new.

Abhishek,

check the LED specs to find, if it will fulfill your wavelengths requirement. Afterall, you don't need all the wavelengths for your measurement.

Back to the temperature problem, you can place the lamp diagonally opposite to the electronics, but away from operator's access. Place the fan next to the lamp and blow the air out of the enclosure. You can place the ventilation holes next the lamp so that freash air can come in and carry over the heat from the lamp. You will be the best person to judge, how to implement this as we have not seen your equipment or the enclosure.