System and method for distinguishing an item from a group of items

A method for distinguishing an item into a first type or a second type comprising the steps of:

• a. transmitting electromagnetic radiation through said item;
• b. receiving said electromagnetic radiation passing through said item;
• c. splitting said received electromagnetic radiation into a first stream and a second stream;
• d. measuring said first stream at a first wavelength;
• e. measuring said second stream at a second wavelength;
• f. said first type comprises clear containers;
• and
• g. said second type comprises light blue containers.

A method for distinguishing an item into a first type or a second type comprising the steps of:

• a. transmitting electromagnetic radiation through said item;
• b. receiving said electromagnetic radiation passing through said item;
• c. splitting said received electromagnetic radiation into a first stream and a second stream;
• d. measuring said first stream at a first wavelengh;
• e. measuring said second stream at a second wavelength;
• f. said first type comprises PEN;
• and
• g. said second type comprises PET.

A method for distinguishing an item into a first type or a second type comprising the steps of:

• a. transmitting electromagnetic radiation through said item;
• b. receiving said electromagnetic radiation passing through said item;
• c. splitting said received electromagnetic radiation into a first stream and a second stream;
• d. measuring said first stream at a first wavelengh;
• e. measuring said second stream at a second wavelength;
• f. splitting said received electromagnetic radiation into a third stream and a fourth stream;
• g. measuring said third stream at a third wavelength;
• and
• h. measuring said fourth stream at a fourth wavelength.

A method for distinguishing an item into a first type or a second type comprising the steps of:

• a. illuminating said item with electromagnetic radiation;
• b. receiving the fluorescence emitted by said item;
• c. splitting said received fluorescence into a first stream and a second stream;
• d. measuring said first stream at a first wavelength;
• e. measuring said second stream at a second wavelength;
• f. wherein said electromagnetic radiation is black light;
• g. said first wavelength is substantially 390 nanometers;
• and
• h. said second wavelength is substantially 425 nanometers.