Seed Production of Vegetable, Tuber and Spice Crops (2+1)

4. Colour Separator

• The colour separator is used to separate discoloured seed, greatly of lower quality.
• Separation based on colour is necessary because the density and dimensions of discoloured seed are the same as those of sound seed, so other machines are not effective for separation.
  
• Electronic colour separation uses photocells to compare the seed colour with “background” which are selected to reflect the same light as the good seed.
  
• Seed that differs in colour is detected by the photo cells, which generate an electric impulse.
  
• The impulse activates an air jet to blow away the discoloured seed.