Absorptivity and Emissivity Coefficients for Steel

http://www.engineeringtoolbox.com/emissivity-coefficients-d_447.html

and you get emissivity values for some usual materials.

As a general recommendation before asking CR4 you should look with a research engine help if you cannot get some information from different links.

The one above is part of the "engineering box"

Roughness affects the values due to its micro geometry: due to repeated reflections in the roughness less light is reflected in the observer direction and more light is absorbed due to same repetition since at every contact part of light is reflected and part absorbed.

Hope it will help.

This is one heck of a difficult question!

Are you looking for full spectrum? Just Heat? Cosmic rays? Light in optical range? The whole deal?

milo

Hi Milo.

Thank you for answering my question. This was your answer: "Are you looking for full spectrum? Just Heat? Cosmic rays? Light in optical range? The whole deal?"

I am conserned about heat.

Hello Nick Name.

You are commenting on my question, and pointing out that I should check available sources before going to CR4. I have already checked what I can find of info in the company's library, and also tried on the internet. But the info found is like the table in The Engineering Toolbox, and this info is not adequit for my purpose.

Kind Regards

Atle

Looking through my old Heat Transfer book, it shows the emissivity of unpolished stainless steel to be 0.21. The absorptivity is 0.5.

I don't know how accurate these numbers are but, through refreshing myself on heat transfer, I believe that these properties change with temperature. You might want to contact a steel vendor to find some properties before designing.

Try This:

http://adsabs.harvard.edu/abs/1979JAP....50.1071W

This one charges: http://www.springerlink.com/content/25jn527q57760081/

milo now we'll get top work on eemissivity. lunch first