How Do You Convert Radiant Power to Irradiance for Solar Radiation Testing?

[jspec26]

Alright, I'm new to the forum, and I've got to say, it is quite impressive. Okay, my question: How do I convert radiant power (uW/10nm/Lumens) to W/m^2? I am conducting a simulated solar radiation test. I need to know the spectral power distribution of a certain metal hallide bulb. The manufacturer provided a chart of radiant power/wavelength. The standard I'm testing to (MIL-STD-810F) has tolerance bands in the UV, VIS, and IR that the bulb must conform to. The values given are in W/m^2. I have an eppley pyranometer, but it measures irradiance across the whole spectrum, I do not have filters available at this time. I'm sure there's got to be some formula for this. I have not taken calc yet, but have support from several engineers here as far as the math goes. Any help would be appreciated. Thanks!

 

[member 553083]

To convert radiant power (uW/10nm/Lumens) to W/m^2, you will need to convert the radiation intensity based on the wavelength of the light source. This can be done using the following formula:Radiant Power (in uW/10nm/Lumens) x (Wavelength in nm / 1000) = Radiant Power (in W/m^2).For example, if you have a metal halide bulb with a radiant power of 500 uW/10nm/Lumens at a wavelength of 450 nm, then the corresponding radiant power in W/m^2 would be 0.45 W/m^2.Once you have calculated the radiant power for each wavelength, you can then use this data to compare it to the tolerance bands in the UV, VIS, and IR that the bulb must conform to in order to pass the MIL-STD-810F test.