To investigate the Lambert’s direction law (cosine law).



This law states that the radiant intensity  of the radition emitted by a flat source is the same from any direction. However the irradiance drops with the cosine of the angle φ




  1. Heat Source
  2. thermopile for measuring the radiation,on rotating mounting.
  3. Luxmeter for measuring the luminous intensity on rotating mounting.
  4. Absorption plates with temperature measurement points.
  5. Colour filters(red,yellow,infrared)and an aperture with clamping mount.
  6. Swevelling light source.
  7. Frame for the components.