| The
technology of bar coding is based on the recognition of dark and light
elements of defined dimensions according to the rules defining the
transition of characters into such patterns, known as the symbology
specification.
The bar code
symbol, as a machine-readable data carrier, must be produced in
such a way as to be reliably decoded at the point of use, if it
is to fulfill its basic objectives. Standard methodologies have
been developed for measuring and assessing the quality of the symbols
for the process control and quality assurance purposes during symbol
production as well as afterwards. This standard is ISO/IEC 15416
The process
of checking bar code print quality is called verification. This
process must use a reading devise and software that is manufactured
under ISO/IEC 15426-1, bar code conformance specifications.
Normal every
day bar code input devices, such as laser, wand, and CCD scanners
are not manufactured to the ISO/IEC 15426-1 standard and therefore
cannot be used as verification equipment. They will only read, or
not read, the bar code. They will not analyze the bar code and tell
you what defects, if any, exist in the code. Furthermore, because
scanners are not calibrated on a regular basis like verifiers, one
scanner may read a bar code and another may not. If you want to
verify, you must use a verifier.
Note:
The bar code print quality standard for two-dimensional codes reference
number ISO/IEC 15415:2004(E) was officially released in 2004.
The bar code
verifier conformance - part 2: two-dimensional, is currently being
worked on, with no completion date announced. It will be published
as ISO/IEC 15426-2.
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