Socket Mobile Secure Digital Scan Card Series 3 - Manual (Page 42)

Appendix D
Decode Zone
The decode zone is a function of various symbol characteristics
including density, print contrast, wide-to-narrow ratio, and edge
acuity. The minimum element width (also known as the “X
Dimension”, “size” or “symbol density” of a bar code) is the
width in thousandths of an inch (or ‘mils’) of the narrowest
element (bar or space) in the bar code. The figures shown are
the typical scanning distances (Depth of Field) for selected bar
code sizes.
For example, the SD Scan Card 3E should be able to scan a 10 mil
bar code when the bar code is positioned between 1.25 and 7.5
inches from the nose of the scanner.
The maximum readable length of a bar code symbol (Width of
Field) at any given range is also shown. In the example above,
the maximum length of a 10 mil bar code scanned at a distance
of 7.5 inches is approximately 8 inches including the quiet zone.
SDSC 3E
42 | A PPENDIX D: D ECODE Z ONE