Radiation - Surface Emissivity Coefficients
Radiation emissivity of common materials like water, ice, snow, grass and more. The emissivity coefficient indicates the radiation of heat from a body according to the Stefan-Boltzmann Law, compared with the radiation of heat from an ideal black body where the emissivity coefficient ε = 1.
About Emissivity Coefficients
The emissivity coefficient - ε - indicates the radiation of heat from a body according to the Stefan-Boltzmann Law, compared with the radiation of heat from an ideal black body where the emissivity coefficient ε = 1.
Emissivity values range from 0 to 1, where:
- ε = 1 represents a perfect black body (ideal radiator)
- ε = 0 represents a perfect reflector (no radiation)
- Materials typically have values between 0.8 and 0.99
Key Points:
- Higher emissivity means the material is a better radiator
- Most natural materials have high emissivity coefficients (0.9+)
- Emissivity can vary with temperature, surface condition, and wavelength