Table of Emissivities in Three Popular Spectral Regions

by Administrator on May 9, 2009 · 2 comments

The Table of Emissivity on the INFRAPOINT Messtechnik GmbH website, posted in 2009 (No longer available online) had summary data for a wide variety of materials broken down into three distinct spectral regions for the wavelength regions where the majority of infrared radiation thermometers and Infrared Thermal Imaging cameras operate.

First and second are tables that deal with the narrow spectral bands about 0.9 µm and 1.6 µm, the regions where many Silicon (Si) photovoltaic detectors (peak wavelength response: (0.9 µm) and both Germanium (Ge) and Indium Gallium Arsenide (InGaAs) (nominal wavelength region (0.7 – 1.6 µm) are used.

The third table cover the 8 – 14 µm waveband where most “low” (near ambient) temperature IR thermometers and thermal imaging sensors operate.

It has been reproduced here below in the spirit of Internet openness from our archives. We hope there is no problem in doing so and if any heir or assigns of INFRAPOINT Messtechnik GmbH wishes to keep this information secret, obviously against the original intent of INFRAPOINT, please contact us according to our webpage contact information.


    Table of emissivity        
  The emissivity ? (radiant emittance factor) is the relationship of the radiated intensity of a body to the intensity of a blackbody of the same temperature.
It is the most important factor, in order to determine of an item exactly.

If you want to measure the surface temperature with an infrared thermometer the emissivity must be known and correct adjusted
on the instrument.
               
   Material  Emissivity     Material  Emissivity  
  Metals Wavelength
0.9 µm 		 Wavelength
1.6 µm 		   Non metals Wavelength
8 – 14 µm  		  
               
  Aluminium, bright 0.05 – 0.25  0.05 – 0.25    Asphalt  0.95   
  Aluminium, anodized 0.2 – 0.4  0.1 – 0.4    Concrete 0.95  
  Chrom, bright 0.28 – 0.32  0.25 – 0.3    Gypsum 0.85 – 0.95   
  Iron, oxidised 0.4 – 0.8 0.5 – 0.9    Graphite  0.75 – 0.92   
  Iron, not oxidised 0.35 0.1 – 0.3    Glass*, pane  0.80   
  Gold, bright 0.02 0.02    Rubber 0.85 – 0.95   
  Copper, bright 0.06 – 0.20 0.06 – 0.20    Wood, natural 0.8 – 0.95   
  Copper, oxidised  0.5 – 0.8  0.7 – 0.85    Chalk 0.98   
  Magnesium 0.03 – 0.8  0.05 – 0.3    Ceramics 0.85 – 0.95   
  Brass, bright  0.8 – 0.95  0.01 – 0.05    Plastics 0.85 – 0.95   
  Brass, oxidised  0.65 – 0.75  0.65 – 0.75    Masonry 0.85 – 0.95   
  Nickel, oxidised  0.8 – 0.9  0.4 – 0.7    Human skin 0.98   
  Platinum, black  -  0,95    Oil paints 0.85 – 0.95   
  Silver  0.02  0.02    Paper  0.85 – 0.95   
  Steel, melted 0.30  0.20 – 0.25    Porcelain 0.85 – 0.95   
  Steel, oxidised  0.8 – 0.9  0.8 – 0.9    Quartz  0.8   
  Steel, bright 0.40 - 0.45  0.30 – 0.4    Carbon black 0.95   
  Titanium, bright 0.5 – 0.75  0.3 – 0.5    Chamotte  0.85 – 0.95   
  Titanium, oxidised  -  0.6 – 0.8    Textile, Drapery 0.85 – 0.95   
  Zinc, bright 0.6  0.4 – 0.6    Tone 0.95   
  Zinc, oxidised  0.5  0.05    Water 0.95  
  Tin 0.25  0.1 – 0.3    Cement  0.9   
* The emissivity of glass (0.95 – 0.97 µm) is in the range of 4.5 – 7 µm particularly high.
Glass has there an absorption band (spectral range, where materials absorb radiation).
To measure glass surface temperatures, the best wavelength is at 5.14 µm, because
the measurement at this range is not affected by absorption bands such as carbon or hydrogen.

Tagged as: , , ,

{ 2 comments… read them below or add one }

Frank Stake July 14, 2011 at 3:11 pm

the above link ” Table of Emissivity on the INFRAPOINT Messtechnik GmbH website (Click here to visit) ”

does not seem to work, it goes to the hompage of lumasense technologies, not data tables

any help is appreciated

Administrator July 27, 2011 at 7:45 pm

Thanks for the “Heads Up”. We had the same experience as you did. It looks like Lumasense Technologies has taken over the web name for Infrapoint. We didn’t find any distinct INFRAPOINT Messtechnik web presence. We were going to remove the link as a result, but found an archived version of it and have amended the page accordingly.

Previous post:

Next post: