6.
Def: Defects
The worst-case change in reflectance within a single bar or space is a defect. The largest difference in reflectivity
found in a single bar or space is measured as a percentage of the symbol contrast and assigned a letter grade.
Defects measure breakups or voids within bars, ink spots in spaces, or even the grain of a substrate in spaces.
Def %
Grade
≤ 15
A (4.0)
≤ 20 (but greater than 15)
B (3.0)
≤ 25 (but greater than 20)
C (2.0)
≤ 30 (but greater than 25)
D (1.0)
> 30
F (0)
7.
DCD: Decode
The widths of each bar and space are measured and used to interpret the data content of the barcode according
to a specific mathematical formula appropriate for the barcode type. If the barcode cannot be decoded according
to the formula, the accuracy of the bar and space widths are inadequate. The printout shows the number of scans
decoded over the number of scans taken, for example 8/10 means 8 out of 10 scans decoded.
8.
DEC: Decodability
Determines how accurate the bar and space widths are and how easily the widths can be determined. A perfectly
accurate barcode has 100 percent decodability, but decodability as low as 25 percent is often acceptable.
Decodability is the percentage of the overall tolerance range for a bar or space width that is not used up by
inaccuracies.
DEC %
Grade
≥ 62
A (4.0)
≥ 50 (but less than 62)
B (3.0)
≥ 37 (but less than 50)
C (2.0)
≥ 25 (but less than 37)
D (1.0)
< 25
F (0)
9.
QZ: Quiet Zone
Quiet Zone refers to a dedicated amount of blank space on the left and right of the barcode. Each symbology
specifies a minimum quiet zone.
47
Grading Standards and their Parameters
