[Radiance-general] Re: translucent panel ( trans material )

[Andrew McNeil]

Hi Coralie,

I¹m not familiar with Spectralon or if there are different varieties of
spectralon, but all the hits of my quick search reveals a substance with
high diffuse reflectance.  And your measurements suggest high diffuse
transmission.  Is it possible that you are confusing Td with Rd?  That would
explain concerns regarding inconsistent transmission values for front and
back.

After talking with a materials guy, I now know that it is possible for a
composite material to have different absorbance depending on direction of
travel (ie if you have a silver coating on one side of glass, light from one
side will pass through the glass twice while light from the other side may
not pass through the material at all).  So for me that is no longer a
puzzle. 

Andy



On 12/18/09 9:45 AM, "Coralie Cauwerts" <coralie.cauwerts at uclouvain.be>
wrote:

> Hi all,  
>  
> Thanks for your responses.
> Values were measured with a spectrophotometer UV-VIS-NIR. The reference is a
> spectralon. I know that measurements are only indicative because some errors
> can occur when diffuse material is measured with this kind of method but I
> have no other source of information about the material.
> In my model, only the ³interior side² of the glass is visible.
> Andrew, I agree with your correction, I saw my mistake yesterday Š
>  
> Coralie
> ------------------------------------------------------------------------------
> -----------
> Coralie Cauwerts
> Researcher
> Université catholique de Louvain
> Belgium
>  
> 
> 
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