Hand Held Products IT4800 - Manual (Page 23)

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Module Errors
Module Errors are individual errors within fixed pattern/data areas. Although
often benign, Module Errors in the fixed regions of a symbol can signal a fault
that, in some instances, will prevent proper decoding. They can generally be
corrected by using a larger X-dimension and/or cleaning up the print process to
eliminate stray ink, voids, and other causes of inconsistency in the print.
Print Growth (Horizontal and Vertical)
Print Growth is a measure of the growth or shrinkage of the bar widths (2D
stacked) or element/module (2D matrix) width and/or height. A low Print Growth
grade indicates print conditions that expand or shrink the apparent size of the
dark bars or elements, which can cause them to optically disappear. In 2D
matrix symbols, if the growth/shrinkage in one direction is larger than the other,
this can indicate excessive drag in the direction of label travel. Potential areas
of correction include adjusting the print process (e.g., ink flow, transfer heat,
print speed), adjusting the original bar code symbol graphic or pattern (through
techniques such as undercutting), or by making the symbol larger.
Row Height
Row Height is an approximate measure of the average height of the elements in
a row, which indicates growth or shrinkage of the element widths. In 2D stacked
symbologies, row heights of less than the recommended height can impede
hand held scanning. This can be corrected by graphically stretching the sym-
bol.
Symbology
Symbology is the symbology type that has been tested. A symbology is a stan-
dard means of representing data in a bar code form. Each symbology specifica-
tion sets out its particular rules of composition or data architecture.
Useful Row Height
Useful Row Height is the measured Row Height times the Codeword Yield. A
low Useful Row Height usually indicates print conditions where rows interfere
with their adjacent neighboring rows, creating a dead band of wasted scanning
in between. Useful row height scales these interfering rows to the printed row