RJS Inspector D4000 SP (FIRMWARE version A.06 and Later) - Manual (Page 44)

Appendix C Operator
’s Guide
RJS, Minneapolis, MN 002-5572
Appendix C (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 need-
ed 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 ele-
ment 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 de-
codable)
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