REA ScanCheck 3n Operating Manual page 41

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GS1 Global has specified corresponding aperture settings for all GS1 code types in its "General
Specifications" that are to be used for code verification of GS1 codes. (The current version can be
obtained via the GS1 Internet site, see Appendix 5)
Source: Table Copy from the Current Version 10 of the GS1 General Specifications, Chpt. 5.5
In a closed automation application, the aperture can be determined based on the optical aperture of
the bar code scanner used.
The aperture used for code verifications, however, should always be smaller than or at maximum equal
to the scanner aperture.
If the aperture is selected too large, the measurement light point will be wider than the smallest width of
the narrow bar or gap in the code. This causes a worse evaluation for the parameter "edge contrast"
and, consequently, for the parameter "modulation" during a verification.
A smaller aperture remains without effect if the bar code is of good quality. When using smaller
apertures, any defects present have greater effect on the "defects" parameter.
© REA Elektronik GmbH REA ScanCheck 3 - August 2010
Page 41 of 89
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