Symbol P470/P370, Руководство по продукции

Страница: 55 / 208

3-23
Operation
Right Wrong
Hold at an Angle
Do not hold the scanner directly over the bar code. Laser light reflecting directly back into
the scanner from the bar code is known as specular reflection. This strong light can “blind”
the scanner and make decoding difficult. The area where specular reflection occurs is
known as a “dead zone.”
You can tilt the scanner up to 65° forward or back and still achieve a successful decode.
Simple practice quickly shows what tolerances to work within.
Figure 3-2. Maximum Tilt Angles and Dead Zone
65
65
Scan
Beam
Scan
Beam
Bar Code Bar Code
Bar Code
Shaded area represents
dead zone ( 2 )
+
_