Blackbodies

The RET Theory

February 23, 2008

Ircon, Inc., a leading producer of industrial radiation thermometers, line scanners and quantitative thermal imagers, in its training programs for many years used to teach something they called the RAT Theory. Reflectance, Absorbtance and Transmittance, or the coefficients of them, abbreviated as R, A &T must sum to 100%, or R + A + T=1. [...]

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NASA Tech Reports Emittance Abstracts

September 20, 2007

A Search on the NASA website results in the following abstracts   DETERMINATION OF THE EMISSIVITY OF MATERIALS Author(s): Askwyth, W. H. Abstract: Space power systems – emissivity of candidate materials for snap-8 powerplant NASA Center: NASA (non Center Specific) Publication Year: 1962 Added to NTRS: 2006-11-06 Accession Number: 63N11697; Document ID: 19630001823; Report Number: [...]

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Beginner’s Guide to (Spectral) Emissivity

September 8, 2007

Introductory Guide to Emissivity This is an introductory page on the National Physical Laboratory (NPL) website in the UK. It has several such sketches as on the left showing the concept of the “radiometric method” of emissivity measurement and discusses both the concepts and measurement methods used to quantify spectral and total emissivity values. The [...]

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Red, White & Blue Blackbodies?

September 5, 2007

It is not an oxymoron, nor a quote from Yogi Berra. Real Blackbodies do not exist, at least on Earth. Only approximations or simulations are real. We use them to calibrate IR Thermometers, Radiation Pyrometers and Thermal Imagers. Technically they should have a spectral emissivity very close to 1.0. How close, you might ask? Read [...]

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Blackbody Radiation Visual Simulator

August 21, 2007

A VRML (3-D Virtual Reality Markup Language) demonstration of blackbody intensity distribution versus temperature and wavelength (This used to be on the University of Massachusetts website, but now is loacted on another site that its creator, Karen Strom has posted). It shows the shape of the Plank function for temperatures ranging from 1,000 K to [...]

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