Machine Parts

Real surfaces on of the best examples are not perfectly diffuse and hence the intensity of emitted radiation is not constant over all directions. The characteristically different behavior of electric conductors and mono-conductors.   Conductors emit more energy in a direction having a large azimuth angle. This behavior more explained with basic electromagnetic wave theory A sphere conducted and mono conducting material will have the opposite behavior and will appear bright in the center and dark around the edge. Reflectance and absorptance of thermal radiation from real surfaces are a function not only of the surface itself but also the surroundings . The properties are dependent on the direction and wave length of the incident radiation .   But the distribution of the intensity of incident radiation with wave length may be a very complicated function of the temperatures and surface characteristics of all the surfaces which incorporate the surrounding