©2005 Nordic ID Oy
Nordic ID PL3000 user manual, v. 2.4, March 2006
77
Appendix B - Code reading distances and requirements
This appendix explains some basics of reading distances and the specification for some of the supported
codes.
Glossary of terms:
Mil:
One thousand of an inch, ~0,0254mm
X dimension:
Also known as “code
size” or “symbol density” of a bar code. In a bar code symbol, data is conveyed by
the patterns and relative widths of the bars and spaces. The x dimension describes
the minimum element width in mils of the narrowest element (bar or space) in the
bar code.
For 2D matrix symbologies, X dimension refers to the nominal dimension of the
smallest data cell.
The X dimension density of the barcode largely decides how many characters can
be encoded in one inch. The resolution of an imager is also measured by the x
dimension density that the imager can recognize.
The decode zone:
The decode zone is a function of various symbol characteristics including density,
print contrast, wide-to-narrow ratio and edge acuity.
Depth of Field (DoF):
The Depth of Field is the area between the maximum and minimum readable length
of a scan engine and a bar code.
Field of View (FoV):
The Field of View is the maximum readable size of an ID symbology at the given
range.