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Barcode verification is a quality
control check on a barcode symbol to check that the barcode is of good quality
and does not have any faults that would affect the readability of the
barcode. Why
Verify - Verifier Composition - CEN/ANSI/ISO
Why Verify?
- Complicated Structure: The readabilty of a barcode is highly
dependant on the quality of the barcode. Even the simplest fault in
the structure and quality of the barcode can render it unreadable and
therefore useless, or worse cause the barcode to read as a different number, leading to incorrect stock
levels and price charges.
- Difficult to See: Although some faults are visible to the naked eye
the nature of the barcode symbol dictates that the majority of problems will
only be picked up using a highly accurate quality control unit (a barcode
verifier).
- Fines Imposed: If barcodes are destined for the consumer market it
should also be pointed out that many Major Retailers throughout the world are imposing heavy
fines on their suppliers for sub-standard barcodes.
What Does a Barcode Verifier
Comprise?
- Reading Head, Data Analyser, Display: A barcode verifier generally comprises a
reading head, a data analyser and a display screen for the results.
- Portable: In portable units this is could be formed using the reading head
with decoder attached to a hand held box containing the controls and display screen.
- PC-Based: Alternatively there are PC based units where the hardware will
generally comprise a reading head and data analyser and then the controls and results
are shown through the units software on your computer.
- Verifier/Scanner Comparison: The verifier reading head must not be confused with a standard barcode
scanner, they are two totally different pieces of hardware. A barcode
scanner is merely trying to obtain a read from the barcode whereas a verifier is
taking many accurate measurements from the barcode in order to provide data for
the various quality control calculations.
The fact that a barcode can be read by a standard
scanner is no guarantee that it is of acceptable quality. Certain
scanners can take up to 500 scans/second and there is no way of telling
whether it captured the code every time or just captured the odd one.
Also scanners vary greatly and what can be read by one cannot necessarily
be read by another, which is why verification is essential to ensure the
quality of your barcode.
What is CEN/ANSI/ISO
- Standards: Verification equipment is usually described as being of
a certain standard, and this will dictate which quality control calculations it must perform. There are
two main standards for verification, Traditional and CEN/ANSI/ISO.
- Traditional: When barcode verifiers were first developed they only checked for a few main
points which were relevant to the printing technologies of the time, Print
Contrast Signal (PCS) and Bar Deviation being the main two. These
verifiers are known as Traditional grade
verifiers, but they are no longer regarded as acceptable instruments for
quality control for many organisations.
- CEN/ANSI/ISO: As printing technologies have developed new standards have
been set up by
the American National
Standards Institute (ANSI) and the European Committee for Normalization (CEN), and more recently adopted by the International
Standards Organisation (ISO). Verifiers adhering to these standards
are known as CEN/ANSI/ISO grade verifiers.
- Parameters: These new standards offer a far more
comprehensive check on the quality of the barcodes, using seven main parameters:
- Minimum Reflectance
- Symbol Contrast
- Minimum Edge Contrast
- Modulation
- Decodability
- Defects
- Decode
- Gradings: This system uses a grading system of
4-0 (or A-D and F). Most Major Retailers expect codes to be of a grade C or higher,
with the exception of codes printed directly on to corrugated which may be a
grade D for Symbol Contrast and Defects but a grade C for other
parameters. However some retailers are stricter and you should always check with
your individual customers for their requirements.
Click for Information on Axicon's
Verifiers
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