joyban

05/27/2008, 09:57 AM

Hi Sanjay

Ref article "Facts of Light Part1,Part2 and Part 3" we have seen several SPD Graphs for MH and Lamps where we have microwatts per 5nm per lumen on Y axis and wavelength in x axis, these are generally refered to as Relative Spectral Power Distribution Graphs. In such a graph obtained from Light manufacturers how do we calculate the number of photons available from the light source at that particular wavelength ?

or can we convert microwatts per nm per lumen into watts / meter square ?

Regards

Sujoy

Ref article "Facts of Light Part1,Part2 and Part 3" we have seen several SPD Graphs for MH and Lamps where we have microwatts per 5nm per lumen on Y axis and wavelength in x axis, these are generally refered to as Relative Spectral Power Distribution Graphs. In such a graph obtained from Light manufacturers how do we calculate the number of photons available from the light source at that particular wavelength ?

or can we convert microwatts per nm per lumen into watts / meter square ?

Regards

Sujoy