Technical data
Leuze electronic
BCL 600i/BCL 601i
82
15.5 Reading field curves / optical data
Bar code characteristics
M
Module: The narrowest line or space of a bar code in mm
Z
B
Wide character: Wide bars and gaps are a multiple (ratio) of the module. Module x Ratio = Z
B
(Normal Ratio 1 : 2.5)
B
Z
Quiet zone: The quiet zone should be at least 10 times the module, but not less than 2.5 mm.
L
Code length: The length of the bar code in mm including the start and stop characters. The quiet
zone is included depending on the code definition.
S
L
Bar length: height of the elements in mm
Figure 15.5: The most important characteristics of a bar code
The range in which the bar code can be read by the device (the so-called reading field) depends on the
quality of the printed bar code and its dimensions.
Therefore, above all, the module of a bar code is decisive for the size of the reading field.
15.6 Reading field curves
The zero position of the reading distance always refers to the front edge of the housing of the beam exit
and is shown for the two housing types of the device (see figure 15.6).
Please note that the size of the bar code module influences the maximum reading distance and
the width of the reading field. Therefore, when selecting a mounting location and/or the bar code
label, take into account the different reading characteristics of the scanner with various bar code
modules.
A rule of thumb: The smaller the module of the bar code is, the smaller the maximum reading
distance and reading field width will be
Please notice that the real reading fields are also influenced by factors such as labeling material,
printing quality, reading angle, printing contrast etc., and may thus deviate from the reading fields
specified here.
