Now that you understand that, there's one more type of measurement. And that is the "Watts" that is sometimes referred to when talking about the flux, radiant flux, or UV flux. If I can do this without butchering it. Those watts are the total amount of radiometric (for UV light) photon energy that is emitted from the lamps, and is measured by using a different kind of detector than a handheld radiometer like Steve makes or a spectroradiometer that Don uses. Spectral flux will tell you how much energy is emitted at specific wavelengths or bandwidths such as "UVA" or "UVB".
This unit of measurement is simply Watts, or Watts times seconds (joule), and can sometimes give you an idea of how efficiently a lamp produces those photons, or light. That is to say, a 1000W lamp will NOT produce 1000 watts of UV energy. Obviously some of it is "wasted" on visible energy, and some of the electrical watts that are inputted to that lamp are converted to infrared (heat) energy. And even then, some of the infrared is radiant energy carried away by the long infrared electromagnetic waves, and some if lost to conduction through the physical transfer within the material of the lamp body itself.
An "efficient" tanning lamp, whether it's HP or LP, will convert those watts of electrical energy into as many appropriate UV watts of photon energy as possible, and will produce less of the unnecessary visible and infrared watts than a less efficient tanning lamp.
So since you opened up that can of worms, there it is. |