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Lighting Requirements, Industrial/Commercial.

  1. Jun 30, 2009 #1
    Are the lighting requirements stated in lux? Also, where would I go to find out the requirements for various settings? I looked around in the NEC book but didn't really find anything.

    Thanks for the help.
     
  2. jcsd
  3. Jun 30, 2009 #2

    stewartcs

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    Science Advisor

    Local building codes should tell you what type of lighting is required for various buildings as well as CFR and OSHA.

    The requirements are typically given in foot-candles.

    Here is a link from OSHA which should point you in the right direction:

    http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10630

    CS
     
    Last edited by a moderator: Apr 24, 2017
  4. Jul 1, 2009 #3
    For most fixtures, there is some type of polished thin white metal above the lamp used as a reflector. About what would it's hemispherical spectral reflectivity be?

    It is more or less a speculur reflector right?

    Assuming the reflectivity is high, and the upper hemisphere is blocked by this metal, can I double the lumens being emitted in the lower hemisphere, getting Candella*4pi=x Lumens ?
     
  5. Jul 1, 2009 #4
    For a lamp that is stated to have x lumens, is that x lumens total, or x lumens per steradian?
     
  6. Jul 1, 2009 #5
    While we are at it, could someone explain to me what a Candella is? I am not really getting it.

    Okay, so it is a Watt/Steradian. Okay.

    Lets say that when we get a flux of 100 photons passing through a surface per second, that that is equal to one watt.

    So if we have, lets say 50 Candella, we have a flux of 5000 photons passing through a surface whose area equals r^2 per second.

    What I do not get, is, if the Candella is defined this way, then doesn't that mean that the candella is dependent on r? If I were to double r, then i am quadrupling the surface area, and therefore my Candella will go down to a quarter its previous value.

    So what does it mean, when you say a lamp has a candella rating of X, without giving the r that was used to determine that?

    I mean, if I choose a big enough R, I could get the sun to have a candella of 1E-1000
     
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