Avoiding Total Reflection; Determining The Reading Distance - Leuze electronic DCR 248i Original Operating Instructions

• Do not use glossy labels.
• The bar code or DataMatrix code is moved past the reading window with a tilt angle or angle of inclina-
tion of 10° ... 20° (see chapter 6.1.2 "Avoiding total reflection").
6.1.2

Avoiding total reflection

If the illumination light of the code reader is directly incident on the surface of the code at an angle of 90°,
total reflection occurs. The illumination light directly reflected by the code label may overload the code
reader and thereby result in non-reading of the code.
Ä Mount the code reader with a tilt angle or angle of inclination of ±10° ... 20° from vertical.
10° ... 20°
1
Recommended tilt angle or angle of inclination: 10° ... 20°
1 Code label
2 Mounting with tilt angle
3 Mounting with angle of inclination
Fig. 6.1: Mounting with tilt angle or angle of inclination
6.1.3

Determining the reading distance

In general, the read field of the code reader becomes larger with increasing reading distance. This also re-
sults in a decrease in the resolution, however.
The following figures show typical reading distances for the individual optics models of the code reader.
NOTICE
Code reading while in motion is dependent on the code type, code size, cell or modulus size of
the code and the position of the code in the read field of the code reader.
For the relationship between camera distance and reading field size, see the section "Relationship between
camera distance and reading field size".
Reading distances for code reader with N1-optics
NOTICE
Please note that the actual reading distances are also influenced by factors such as labeling
material, printing quality, reading angle, printing contrast etc., and may thus deviate from the
reading distances specified here.
Leuze electronic
2
10° ... 20°
DCR 248i
3
1
Mounting
25