
Appendix M
Operator
’s Guide
RJS, Minneapolis, MN
003-4500
116
is one thing to check in seeking to correct a low
modulation grade
Module
The narrowest expected bar or space width.
Moving Beam Scanner
A laser device that dynamically searches for a bar
code pattern by sweeping a moving optical
beam
through a field of view.
N (wide to narrow ratio)
In symbologies with two element widths, the wide to
narrow ratio of elements is calculated by summing the
average wide bar width and average wide space width
and dividing the sum by 2 times Z. Inter-character
gaps, if applicable, are not included.
N = (avg.wide bar + avg. wide space) / (2*Z)
Nanometer (nm)
A unit of measure used to define the wavelength of
light, equal to 10-9 meter.
Narrow Bar Width (or NBW)
The intended width of the narrow elements dictated by
the application and/or symbology specification. Also
referred to as X-Dimension (X-Dim)
Nominal
The intended value for a specific parameter.
Tolerances are generally specified as positive and
negative deviations from this value.
No-Read (Non-read, Non-scan)
The absence of data at the scanner output after an
attempted scan because of no code, defective
code or operator error.