SpectralEmissivity & Emittance

| Useful Data | Practices Measuring or Avoiding | Background & Theory|

Improving Temperature Measurement of Low Emissivity Targets

Helpful Tips for Users From FLIR

fliratspr118-imageMeer, Belgium — FLIR Systems has published a new technical note that investigates and describes how to use low-cost materials to increase target emissivity to enable accurate measurement using a thermal imaging camera.

Clean, unoxidized, bare metal surfaces such as are found in many R&D applications have low emissivity. Consequently they are difficult to analyse with a thermal imaging camera.

To get good accurate temperature measurements there is a consequent need to increase the emissivity of these problematic targets.

The technical note provides an informative introduction to emissivity and how a target’s emissivity, reflectance and thermal conductivity values are highly dependent on material properties.Read More

Raytek’s Online Spectral Emissivity Guide

Screen Shot of Webpage

Santa Cruz CA, USA — As part of the IR Education section, the Raytek Corporation website contains some useful and well-presented information on Spectral Emissivity, one of the few instrument makers who do so.

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 a summary of the opening statements and links to the actual data pages.Read More

Fluke Calibrator Video

Emissivity makes a temperature difference for infrared thermometers.

In the YouTube video below, Frank Liebman, an engineer with Fluke Corporation’s Hart Scientific Division demonstrates the impact that surface emissivity has on temperature measurement and temperature calibration using a modified Fluke blackbody calibrator and Fluke Thermal Imager.

We were surprised to see that no one commented on this video, despite an ending that leaves one hanging, at least us, with the obvious question: How do you do a radiometric calibration of a surface of unknown emissivity using a Fluke Blackbody Calibrator?

Do you have any ideas?