Electronic Grading » Optical Sorting

Size & Quality Grading
- What can the Auto-sort grade / inspect / detect?

The Autosort can sort potatoes into a maximum of 3 classifications by Size & Quality.

Skin defects like Black Dot, Common Scab, Rhizoctonia (Black Scurf), Silver Scurf, Rot, Greening and Skin Spot, which spoil the general appearance of the skin and are not normally acceptable for pack grade potatoes are detected.

Other defects causing skin discolouration may also be detected. More flexibility is provided using the colour sorting function, which can be used to separate greens or mixed colour batches where red tubers are mixed with white and even red potatoes which have had some skin removed. Malformed or mechanically damaged tubers may be detected using the powerful shape and crack detection analysis.

Basic sizing is provided to allow a function similar to a mechanical sorter. The size of a square hole fitting the potato is estimated to enable oversize, undersize or a special size to be taken out. In addition the length of the tuber is measured which enables a 3 dimensional size classification to be made using a combination of square mesh and length.

A number of grading features are adjusted by the operator to set independent decision levels for the grades between classes. This allows a green potato to directed to the waste grade as well as a small potato, which has no surface defect but is just too small to make grade 1 or 2. Using the grading features it is possible to set a level at which the skin discolouration is sufficiently visible to move the potato into a second grade and a higher level to put the most discoloured potatoes into the third grade. All the images taken of the potatoes are then analysed and classified to the assigned grades. Live pictures of graded potatoes are provided to allow the operator to optimise the operation. As the runs of potatoes change it is to easy adjust the sensitivity to follow the pack requirements.

The adjustments made for one batch of potatoes may be stored for later recall and many stored sets can be held on the computer for rapid switching between batches.

Green & Mechanical Damage
Common Scab
Black Dot
Rhizoctonia/Black Scurf
Silver Scurf
Skin Spot

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© RJ Herbert Engineering 2010