TOMRA 3A

How a optical sorter works

An optical sorter looks at food as it moves past cameras or lasers and picks out the pieces that are bad, the wrong colour or not food at all. A computer decides in a split second, and a puff of air or a small finger pushes the bad piece out of the stream. It does the job of a row of people picking by hand, without getting tired.

1. 01

   Step 1: Spread the product

   A shaker or belt spreads product into a thin, even layer so no piece hides another.

2. 02

   Step 2: Look at every piece

   Cameras, lasers or other sensors view each piece from one or more sides as it passes.

3. 03

   Step 3: Decide

   Software compares each piece with the reject rules set for that product and grade.

4. 04

   Step 4: Reject

   Air jets or fingers push rejected pieces into a separate stream; good product carries on.