RJS Inspector D4000 Auto Optic (FIRMWARE version A.06 and Later) - Manual (Page 45)

Operator
’s Guide
Appendix B
002-5564 RJS, Minneapolis, MN 37
Appendix B (ISO/ANSI Decodability)
ISO/ANSI Decodability Calculations
There is a specified method for calculating Decodability
for each symbol. But the method is generally the same
for all. Each element width in a bar code symbol should
be consistent across the symbol.
In the case of Code 39, two element widths are needed
to produce a symbol. For optimum scanning, each
narrow element, whether a bar or space, should have the
same width dimension. And each wide element should
have the same width dimension.
The Decodability grade indicates the amount of toler-
ance remaining in the width of the most deviant element
in the symbol (the more tolerance remaining, the higher
the grade). Grade
“A” is the highest grade and grade “F”
is lowest. (Even grade
“F”
may be decodable)
The grade is displayed in both its calculated numeric
form and in its alphanumerical equivalent (the ISO15416
and ANSI X3.182-1990).
Decodability Grade Conversions
≥
.62 = A
≥
.50 = B
≥
.37 = C
≥
.25 = D
< .25 = F