Radiation surface absorptivity.
The absorptivity is the amount of radiation absorbed by a surface compared to what is absorbed by a black body.
|Aluminum, dull/rough polished||0.4 - 0.65|
|Aluminum. polished||0.1 - 0.40|
|Asbestos Cement, old||0.83|
|Iron, galvanized old||0.89 - 0.92|
|Light green paint||0.95|
|Limestone||0.33 - 0.53|
|Red clay brick||0.94|