RJS Inspector D4000 - Appendix B: ISO;ANSI Decodability; Decodability Calculations and Grade Conversions

Operator’s Guide Appendix B
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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
tolerance 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