Enter the emitted radiation and the blocked radiation into the Calculator. The calculator will evaluate the Emissivity.
Emissivity Formula
E = ER / BR
Variables:
- E is the Emissivity ()
- ER is the emitted radiation
- BR is the blocked radiation
To calculate Emissivity, divide the emitted radiation by the blocked radiation.
How to Calculate Emissivity?
The following steps outline how to calculate the Emissivity.
- First, determine the emitted radiation.
- Next, determine the blocked radiation.
- Next, gather the formula from above = E = ER / BR.
- Finally, calculate the Emissivity.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
emitted radiation = 50
blocked radiation = 60
FAQs about Emissivity and Radiation
What is emissivity and why is it important?
Emissivity is a measure of an object’s ability to emit infrared radiation compared to that of an ideal black body at the same temperature. It is important because it helps in determining the efficiency of materials to radiate energy, which is crucial in fields like thermal imaging, climate studies, and material science.
How does the type of material affect emissivity?
The emissivity of a material is influenced by its surface properties and composition. Materials with rough, matte surfaces typically have higher emissivity than those with smooth, shiny surfaces. The chemical composition of the material also plays a significant role, as different elements and compounds emit and absorb infrared radiation differently.
Can emissivity change with temperature?
Yes, emissivity can change with temperature. For many materials, emissivity increases as temperature rises, though the rate of change can vary widely depending on the material’s properties and surface condition. This temperature dependence is crucial in accurate temperature measurements using infrared techniques.
Why is knowing the blocked radiation important in calculating emissivity?
Blocked radiation is crucial in calculating emissivity because it represents the portion of radiation that is not emitted by the object, which can include reflected and transmitted radiation. Understanding how much radiation is blocked helps in accurately determining the object’s ability to emit radiation, which is what emissivity measures.
