Spectral Emissivity on Fluke's Website

After the Fluke organization acquired Raytek, many of the original technical webpages were merged into the Fluke Process Instruments webpages.

The links we had on spectral emissivity values for  Raytek's webpages on my original website were changed.

However the data remains the same and still provides useful insights for users of Infrared Radiation Thermometers and Thermal Imaging Cameras.

Of course, the data clearly shows, as it always has, that "Emissivity" is not a simple topic and that, in fact there are some significant spectral variations in emissivity values according to the waveband sensitivity of the IR Thermometer being used and the type of material being measured. There are more, but those details are not detailed here.

Raytek's well-presented information on Spectral Emissivity, was one of the few instrument makers who did so. In fact, I believe they still are unique for their successor organization, Fluke Process Instruments.

Although they just call it plain "emissivity" they then present values for three or four different wavebands, according to the table viewed,

"A Rose by any other name...". There are two pages with disclaimers.

Here's the opening statements in each page and links to them.

"Emissivity - Non-Metals"

"Emissivity Values for Common Materials"

"Emissivity is the measure of an object's ability to emit infrared energy. Emitted energy indicates the temperature of the object. Emissivity can have a value from 0 (shiny mirror) to 1.0 (blackbody). Most organic, painted, or oxidized surfaces have emissivity values close to 0.95. The majority of our IR sensors have an adjustable emissivity feature to ensure accuracy when measuring other materials, such as shiny metals.

"Please note, these values are to be used as a guide only, as emissivity changes depending on the actual material surface and conditions."

Emissivity Table for Non-metals (Note: Shows typical values in four different wavebands)

"Emissivity Values for Metals

Same statement as for Non-Metals

  Emissivity Table for Metals (Note: Shows typical values in three different wavebands)