Inspector 5000
™ Auto Optic
Appendix A
RJS, Minneapolis, MN
003-4500
64
Defects
This parameter can be graded 4.0 to 0.0 (A to F)
Defects are irregularities in bars, spaces and quiet zones.
For example, a dark spot in a space could cause a low
enough reflectance to be mistaken for a bar, and the
extra bar would cause a decode error.
The defect grade is determined by a relationship between
the largest defect in the symbol and the symbol contrast
(the smaller the defect, the better the grade).
Note:
In general, a small aperture used to analyze very wide
elements will cause the largest defects.
Edge Contrast Minimum
This parameter can be graded 4.0 (A) or 0.0 (F), however
multiple scan averaging can results in grading 4.0 to 0.0
(A to F)
Edge contrast is the difference of the reflectance values
of the dark and light components of an edge.
Each element of a bar code has two edges which go from
dark to light. Therefore, each edge has a dark and light
reflectance value component.