Symbol Series 6800 Product Reference Manual page 76

Range
Any scanning device decodes well over a particular working range — minimum and
maximum distances from the bar code. This range varies according to bar code density and
scanning device optics.
Scanning within range brings quick and constant decodes; scanning too close or too far away
prevents decodes. You need to find the right working range for the bar codes you are
scanning. The best general advice is:
t Hold the scanner farther away for larger symbols.
t Hold the scanner closer for symbols with bars that are close together.
t Start scanning at a distance from the bar code, not from direct contact. If the bar
code does not readily decode, move the scanner in closer.
Practice quickly shows what distances to work within.
Operating the Series 68XX
5-13