Operator
’s Guide
Appendix K
002-7858
RJS, Minneapolis, MN
53
Element Reflectance Non-uniformity (ERN)
The reflectance difference between the highest peak and lowest valley within each individual
element and quiet zone. When an element consists of a single peak or valley, its element re-
flectance non-uniformity is zero.
Element Width
The thickness or width of a bar or space as measured from its leading edge to its trailing edge.
Encoded Area
The total linear dimensional space taken by all characters of a code pattern including start/stop
and data.
First Read Rate
The percentage of successful
“reads” of a
bar code symbol on the first attempt.
Fixed Beam Scanner
A bar code reading device wherein coded items pass across a stationary incandescent or LED
light source.
Flexo Film Master
A measurement standard symbol produced by printing the symbol on clear plastic film using the
Flexographic printing process.
Gloss
A phenomenon related to the specular reflection of incident light. The effect of gloss is to reflect
more of the incident light in a specular manner, and to scatter less. This effect occurs at all an-
gles of incidence and should not be confused with the grazing angle which is specular reflection
often referred to as sheen.
Global Threshold (GT)
The global threshold is drawn through the middle of a profile, to distinguish spaces above the
line and bars below. The reflectance value is determined by dividing the symbol contrast (SC)
by 2 and adding the minimum reflectance, Rmin.
GT = Rmin + (SC/2)
GS-1
GS1 designs and implements global standards and solutions to improve the efficiency and visi-
bility of supply and demand chains globally.
Guard Bar
The first and last bars of a bar code symbol usually having the pattern 101. A guard bar gener-
ally follows the leading quiet zone and precedes the trailing quiet zone. This term is used most-
ly for UPC/EAN symbologies.
Infinite Pad Method
The method for measuring reflectance in which the sample substrate being measured is backed
with enough thickness of the same type of substrate so that doubling the number of sheets
does not change the measured value of reflectance.