Slope (2-Color Ratio) Measurements - Fluke Endurance Series User Manual

Endurance® Series
Users Manual
When target emissivity is uncertain or changing, a 2-Color sensor can be more accurate than
a 1-Color instrument as long as the emissivity changes by the same factor in both wavelength
bands. Accurate measurement results are dependent on the application and the type of
material being measured. The emissivity of all real objects changes with wavelength and
temperature, at varying degrees, depending on the material. To determine how to use 2-Color
sensors with your application when uncertain or changing emissivities are a factor, please
contact our sales representative or technical support department.

2.1.4. Slope (2-Color ratio) measurements

The slope is the quotient of the emissivities based on the narrow and the wide spectral range
(first and second wavelength). The factory default preset slope is 1.000.
For information on determining an unknown slope, and for sample slopes, refer to the appendix
of this manual.
The slope is the important parameter for measurements in 2-Color mode!
The emissivity affects only measurements in 1-Color mode.
Experts figured out, that extreme dirt (dust, fingerprints) on the optical lens
or vision window influences the Endurance
Unpredictable temperature readings may result in such a case!
6
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2-Color measurement chain.