Denso BHT-604B User Manual page 39

When unable to successfully read barcodes...
Cause
When the light is focused on the printed
Specular surface of the barcode from directly above,
reflection tthe BHT may not read the code due to
specular reflection.
The barcode may not be read if it is too
Distance from
close to or too far from the BHT reading
barcode
window,
Barcode surface The barcode may not be read if surface is
curvature extremely curved.
Barcode surface The barcode may not be read if its surface
dirt is dirty.
Barcode reading The barcode may not be read if the
window dirt barcode reading window is dirty.
Barcode
Direct sunlight,
affected
ambient light
brightness of the surrounding light.
reading may be adversely
by direct sunlight or the
Barcode Handy Terminal
Countermeasure
Change the BHT reading angle and try again.
Move the BHT slowly toward or away from the barcode
and try again.
Read the barcode at the center of the barcode reading
window.
Wipe the dirt from the barcode and try again.
Blow any dust away with an airbrush, and then gently
wipe the reading window with a cotton swab or similar soft
object.
Read the barcode away from direct sunlight. Adjust the
brightness of the surrounding light when reading indoors.
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