RJS Inspector D4000 Auto Optic (FIRMWARE version A.06 and Later) - Manual (Page 72)

Appendix K Operator
’s Guide
RJS, Minneapolis, MN 002-5564
Edge Contrast (EC) See Edge Contrast(min)
The difference between the space reflectance (Rs)
and adjoining bar reflectance (Rb).
EC = Rs - Rb
Edge Contrast (min)
This parameter grade can be
“A” or “F.” Edge co
n-
trast is the Reflectance difference between adjoining
bars and spaces. The minimum edge contrast is the
smallest value of EC = R space
–
R bar found in the
scan.
The grade is determined by calculating the edge con-
trast of every element in a symbol and then compar-
ing the lowest value to a fixed threshold in the speci-
fication (15%).
If the value is equal to or greater than the threshold,
the grade is
“A.” If the value is less than the thres
h-
old, the grade is
“F.”
Element
A generic term used to refer to either a bar or space
in a bar code symbol.
Element Edge
The location where the scan reflectance profile inter-
sects the midpoint between the space reflectance (R
space) and bar reflectance (R bar) of adjoining ele-
ments. Visual measuring techniques will generally
locate the element edge closer to the center of the
bar.