Hand Held Products IT4710 Benutzerhandbuch

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The hand-held imager has a view finder that projects a bright aiming beam 
that corresponds to the imager’s horizontal field of view.  The aiming beam 
should be centered over the bar code and positioned horizontally over the 
code (no tilt, skew, or rotation).  If the symbol surface is shiny, the reader 
may have to be held several degrees below the normal position to avoid 
specular reflections.

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When testing, attempt to minimize as much movement of the imager as pos-
sible.  Excessive movement can cause variability in PQA results.

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It is best to take multiple reads of the symbol, comparing the PQA results to 
form a better indication of the overall symbol quality.

When you use 2D PQA under the above conditions, you can expect meaningful 
and repeatable results that can be used to make correction adjustments in your 
symbol generation process.

Two-dimensional bar code symbologies come in three distinct varieties or basic 
structures:

1. Stacked or Multi-Row symbologies (e.g., PDF417 and MicroPDF47),

2. 2D Matrix symbologies (e.g., Data Matrix, Aztec Code, QR Code, and Maxi-

code), and

3. Postal (Height-Modulated) symbologies (e.g., Postnet and Planet Code in 

the U.S. and the 4-State codes used in England, the Netherlands (KIX), 
Canada, Japan, and Australia).

Since each of these basic types or structures differ, the 2D PQA outputs are 
quite different to accommodate the quality parameters for each of the classes of 
2D symbols.

2D Matrix symbol