GLOSSARY OF TERMS
AIM - Automatic Identification
Manufacturers, website :
www.aimglobal.org
alphanumeric or alphameric - the
character set that contains letters, digits, and usually other
characters such as punctuation marks. A machine vocabulary that
includes both numerals and letters of the alphabet.
aspect ratio - the ratio of
height to width of a bar code symbol. A code twice as high as it is wide
has an aspect ratio of 2; a code twice as wide as it is high has an
aspect ratio of 0.5.
auto-discrimination - a feature
of certain AIS devices accommodating machine interpretation to define
which of a predetermined set of symbologies is being presented to the
device. In barcoding, that feature
which accommodates the reader in distinguishing, automatically, between
various barcodes. Auto-discrimination implies the capability of a
reader to read multiple symbologies, such as Code 39, Codabar, EAN, UPC,
and so on... automatically, without deleterious effect to first read
rate or substitution error rate. See multicode reader.
automated identification systems (AIS)
- the application of various technologies, such as bar coding, image
recognition, voice recognition, and RF/MW transponders, for the purpose
of data entry to a data processing system, bypassing the key-entry
component of traditional data entry. AIS applications are
characterized by data capture at the site of an event with direct
transmission to a computer or interim storage device, orders of
magnitude reduction in data entry errors, and more timely processing of
the captured data.
automation - the implementation
of processes by automatic means.
background - the area surrounding
a printed symbol.
background reflectance -
measurement of the brightness of the substrate that a bar code is
printed on.
bar - one or two types of
elements comprising a bar code symbol. A bar elements comprising a
bar code symbol. A bar element is the element type that has the
lower average value of reflectance.
bar code - an automatic
identification technology that encodes information in an array of
parallel, rectangular bars and spaces that vary in width.
bar code density - the number of
characters that can be represented in a lineal inch.
bar code label - a label that
carries a bar code and, optionally, other human readable information; it
can be affixed to an article.
bar code medium gain - the value
equal to the background noise received divided into the code signal
received.
bar code reader or barcode scanner
- a device used to identify and decode a bar code symbol.
barcode symbol - an array of
parallel, rectangular bars and spaces that together represent a single
data element or character in a particular symbology.
bar length (bar height) - the bar
dimension that is perpendicular to the bar width. The longer
dimension of a bar.
bar width - the thickness of a
bar measured from the edge closet to the symbol start character to the
trailing edge of the same bar.
bar width ratio - the ratio between the
widest bar or space and the narrowest. In the Uniform Container
Symbol barcode, the wide bars and spaces are 2.5 times as wide as narrow
ones. The recommended bar width ratio for the HIBC symbol and code is
3:0:1
calibration mark or bar – a code bit that provides the scanner with
contrast, speed, or code position information, as required.
carrier sheet – the backing material on which printing plates are
mounted.
CCD (charge-coupled device) – an array (linear or matrix) of
transductive elements wherein packets of electrons are set in each
element as a result of the quantity of light received during an exposure
interval, and where these packets are recovered from the array in the
form of a pulse height-modulated electric signal.
center line – the vertical axis around which character elements are
located for letters, numerals, or symbols of an OCR font.
character – A letter, digit, or symbol that is used as part of the
organization, control, or representation of data. A character is often
in the form of a spatial relationship of adjacent or connected strokes.
A single group of bars and spaces that represent an individual number,
letter, punctuation mark, or other graphic font. A graphic shape
representing a letter, numeral, or symbol.
character alignment – The vertical or horizontal position of
characters with respect to a given reference line.
character density – The dimension, in linear inches, required to
encode one character; measured in characters per inch (cpi).
character parity checking – a self-checking feature of some bar
codes which relies upon values being assigned to the various widths of
bars and spaces within a bar code representation of a given character.
The presence of character parity checking adds security to the bar code,
because all the characters share a common specific pattern.
character reading – reading of alphabetic and numeric characters and
symbols by optical means.
character set – those characters which are available for encoding
within a bar code system or other type of symbol set, such as OCR-A,
OCR-M.
character spacing – the horizontal distance between two adjacent
characters.
check character/checksum/check digit – a character included within a
symbol whose value is based, mathematically, on other characters within
the symbol. It is used to perform a mathematical check to ensure the
accuracy of the read.
clear area – a clear space, containing no dark marks, which precedes
the start character of a symbol and follows the stop character. The
clear area of a bar code should be 10times the size of the narrowest bar
in the code or.250 inch, whichever is greater. That region of a document
reserved for OCR characters and the required clear space around these
characters. Also called quiet zone.
clock – a device that generates periodic signals used for
synchronization; a register whose contents change at regular intervals
in such a way as to measure time.
clock mark/clock bar – a timing mark or bar used in certain codes.
closed system – one where a central authority has control over the
resolution of all bar code readers and the element size of al bar code
printers employed within the system.
Codabar – a bar code format in which four bars and three spaces are
used to represent the digits 0 through 9 and certain special characters.
The code is characterized by four unique start/stop codes, variable
intercharacter spacing, and code density of up to 10 characters per
inch.
code – a set of unambiguous rules specifying the way in which data
may be represented, such as the set of correspondence in the standard
code for information interchange; in telecommunications, a system of
rules and conventions according to which the signals representing data
can be formed, transmitted, received, and processed; in daa processing,
to represent data or a computer program in a symbolic form that can be
accepted by a data processor. See also bar code.
code density – see bar code density.
code label – see bar code label.
code medium – the material used to construct a machine-readable
code. Such materials may be retroreflective, luminescent, magnetic,
opaque, transponder, or conductive.
code medium gain – see bar code medium gain.
code plate – a plate to which code marks are affixed in a fixed or
adjustable code configuration or pattern.
code reader/code scanner – a device that examines a spatial pattern,
one part after another, and generates analog or digital signals
corresponding to the pattern.
Code 11 – a code developed by Intermec that encodes 11 different
characters (0 through 9 and -). Each character has three bars and two
intervening spaces, for a total of five elements. Of these five
elements, two are wide and three are narrow, except for the 0,9, and –
characters, which have only one wide element and four narrow elements.
Nominal bar code density is 15 characters per inch.
Code 39/3 of 9 Code – a code developed by Intermec that encodes 43
data characters (0 through 9, A through Z, six symbols, and a space).
Each character is represented by nine elements (five bars and four
spaces); three of the nine elements are wide and six elements are
narrow. Nominal bar code density is 9.4 cpi (high density) with other
densities of 8.3, 5.7, 3.0, and 1.7 cpi. Code 39 has been recommended
for usage or included in standards prepared by the following independent
organizations: AIM (Automatic Identification Manufactures), ANSI
(American National Standards Institute), DOD (Department of Defense/LOGMARS),
DSSG (Distribution Symbol Study Group), AIAG (Automotive Industry Action
Group), and HIBCC (Health Industry Bar Code Council).
Code 93 – a code developed by Intermec that includes a character set
that is identical to Code 39, Each character is constructed from nine
modules arranged into three bars with adjacent spaces. Nominal bar code
density is 13.9 cpi.
Code 128 – a code developed by Computer Identics
that encodes the full ASCⅡ
character set of 128 characters. Each character is represented by 11
modules and four bar widths.
contact reader/contact scanner – a code reader (scanner) which
requires physical contact between the code medium and the scanner.
continuous code/continuous bar code symbol – a bar code or symbol in
which the space between two characters (intercharacter gap) is part of
the code, such as USD-1 (Interleaved 2 of 5 Code). A continuous code is
the opposite of a discrete code.
continuous form – form manufactured from a continuous web of paper
that is not cut into units prior to execution. The continuous form may
be perforated. Distinguished among bar code printers from cut sheet
printers.
continuous ink jet – a method of printing which uses print heads
that spray a continuous stream of charged ink droplets at the paper.
Control of an electromagnetic filed between the ink jets and the paper
determines whether the ink droplets reach their destination or are
electrically deflected and siphoned away by a suction tube. One of two
ink jet technologies, the other being drop on demand. Continuous ink jet
can give a finer line with greater control of registration of the
applied ink. Also called Hertz technology.
contrast – amount of difference in reflectance between the dark bars
and the light spaces of a bar code; measured by PCS (print contrast
signal).
cut
sheet – form delivered as individual sheets. Distinguished among bar
code printers from continuous form printers.
data acquisition –
the process by which data are moved from the site of an event to an
environment in which the data can be processed into meaningful
information.
data collection system – a system that consists of input devices
located at points where data are created. Data are manipulated into
these devices and immediately transmitted, by cable, telephone line, or
radio signal, to a central location, usually in or ner a computer room,
where data are automatically recorded. Data may also be transmitted to a
storage medium, such as a tape, disk, or semiconductor, and be
transferred later to the host computer for data manipulation.
data element – a specific item of information appearing in a set of
data; in the following set of data, each item is a data element: the
quantity of a supply item issued, the unit rate, the amount, and the
balance of stock funds on hand.
decoder logic – the electronic package that receives the signals from
the scanner, performs the algorithm to interpret the signals into
meaningful data, and provides the interface to other devices.
densitometer – an instrument that measures the light reflected from a
surface. It is used as a control instrument to check the uniformity of
print color.
density – the mass of a unit volume; opacity; color strength. See also
symbol density.
depth of field – the distance between the maximum and minimum plane in
which the code can be read. See Figure 13-1.
detector – a device that converts optical energy to electrical energy,
such as a PIN photodiode.
diffuse reflection – the process by which incident flux is redirected
over a range of angles.
diffusion – a spreading out or equalized dispersion of a material,
force, or condition into the surrounding medium, such as the diffusion
of heat by conduction, the diffusion of light through a translucent
material, reflection from a rough surface, or the diffusion of gasses,
liquids, or granular solids into the surrounding medium.
diagnostic verifier – a device that automatically evaluates the quality
of a film master or a printed code. Measures the quality of the symbol
against the proper specification for the printing of the symbol, giving
relative and absolute measurements of the print contrast signal,
absolute light reflectance, absolute dark reflectance, bar widths, space
widths, percent decode, and the variance of the printed symbol from the
specifications.
discrete code/discrete bar code symbol – a bar code symbol in which the
intercharacter gap is not part of the code and is allowed to vary
dimensionally within wide tolerance limits.
EAN - European Article Numbering;
now also IAN - International Article Numbering; the international
standard barcode for retail food packages corresponding to the Universal
Product Code (UPC) in the US. UPC is a subset of IAN and, where a
barcode scanner is equipped to read EAN, UPC can also be decoded, but a
reader equipped to read UPC may be unable to decode EAN. The EAN
and UPC symbols were developed by IBM and introduced into the market in
1971.
edge error/edge roughness -
irregularities in the average or nominal edge of a bar code element due
to printing.
encoded area - the total lineal
dimension consumed by all characters of a code pattern, including
start/stop and data
expendable code - a code label
which is disposed of after the completion of its designated use.
field - any group of characters
defined as a unit of information. This differs from a line, as one
line may contain several fields
field of view - the lineal
dimension defining the length of a code that can be read in one scan;
particularly significant in
laser scanner,
retroflective, and array te3chnologies, as the readable code length
becomes a function of the ability of the operator to continue the
movement of the wand across the code in a smooth fashion in order to
successfully read the Symbol.
filter - a medium that attenuates
electrical or optical energy signals of some frequencies more than
others. A filter may transmit one band of frequencies. and reject
all other frequencies.
firmware - software that accepts
parameters for programming
uniquely required by a user.
fixed base reader
- a barcode scanner that is mounted in a stationary fashion to intersect
the plane of bar code symbol passing before the scanner. Often
employed in conveyor and transport systems. differs from a
hand-held bar code
scanner.
fixed length (code and field) -
referring to a symbol or code in which the data elements must be of a
specific length. Length is fixed to establish field position in
the data structure or to provide additional read reliability in
scanning.
font - a family or assortment of
characters of a given size and style of printer's type
format - the geometric
construction rules that define a particular bar code
guard bars - the tall bars used
at the sides and centers of the UPC and EQN bar code symbols to provide
reference points for scanning.
handheld scanner - a scanner
held and operated by a human, thus enabling the scanner to be brought to
the symbol
Image camera /
sensor - a photo-optical device
used in pattern recognition applications. The received image is compared
to the mathematical representation of the correct image or set of
images. The received image is decoded based upon stored
predetermined representations. This device can be used in quality
inspections and optical character recognition applications.
image orientation - orientation
of the image on a film master
infrared -
the band of light wavelengths too long for response by a human eye.
This band is represented by waves between 750 and 4 million nanometers
in length. Photodiodes operating with this light source are
usually specified at a peak response of around 900 nanometers, some
barcode scanners are able to generate infrared red light and decode the
barcode labels which has been protected by a piece of blacken plastic
sheet.
Interleaved 2 of 5 Code - a code
developed by Intermec for Computer Identics that encodes the ten digits
0 through 9. The name interleaved 2 of 5 is derived from the
method used to encode two characters. In the symbol, two
characters are paired, using bars to represent the first character and
the interleaved spaces to represent the second character. Each
character has two wide elements and three narrow elements, for a total
of five elements. The specification for this bar code is set forth
in MHI/AIM US-1, and it can achieve a maximum density of 17.8 characters
per inch.
item code - in the UPC system,
the five-digit number that each
manufacturer assigns to each product. Corresponds in the HIBC
system to product/catalog number (PCN).
Kiss impression - the lightest
possible impression which transfers the film of ink from the transfer
roll to the plate and from the plate to the material being printed.
Label - a piece of paper, cloth,
polymer, metal, or other material affixed to something and indicating
its contents, destination, or other information.
laser - an
acronym for Light Amplification by the Stimulated Emission of Radiation.
A coherent, monochromatic light source having the common characteristics
of an active material to convert energy into laser light, a pumping
source to provide power or energy, optics to direct the beam repeatedly
through the active material so that it becomes amplified and the optics
to direct the beam into a narrow cone of crystal lasers, gas lasers,
liquid lasers, and semiconductor lasers, Crystal lasers use a crystal
such as a ruby for an active medium. Gas lasers use gases in
combination, such as helium and neon, as an active medium. Liquid
lasers use medium. The semiconductor laser is made from a material such
as gallium arsenide. A laser used in cutting or welding has a
power output of hundred to thousands of Watts, whereas a laser employed
in barcode scanning has a power output in the micro Watt to milliWatt
ranges. Output power and safety considerations of laser are
regulated by the FDA Agency Center for Device and Radiological Health.
laser diode - a laser made from a
semiconductor pn junction. Historically, laser diodes were of
gallium-arsenide composition. Theses devices emitted light only in
the infrared portion of the light spectrum. Recently advances in
laser diode technology have permitted light emission in the near
infrared region.
light pen - or wand, a pen-like, contact reader that is
hand-held, typically employing an infrared or panchromatic red light
source.
light source - light energy is emitted
in straight lines from one of two source types, the point source and the
extended source. The point source of light energy illuminates a
point in space from several directions. Light sources for bar code
scanning equipment are typically infrared, visible red, and
incandescent. The source wavelength of He-Ne laser light is
precisely 632.8 nanometers.
magnetic
code reader - a remote code reader that reads and identifies by
the detection of the presence of absence of a magnetic field.
magnetic ink character recognition
- MICR; the machine recognition of characters printed with ink that
contains particles of a magnetic material. Commonly used in check
printing within the banking and financial community.
maximum bar reflectance - the
maximum reflectance within any bar when the measuring aperture is wholly
contained within a bar. Note that the printing tolerance for a
particular symbology may result in the measuring aperture being larger
than the width of the bar elements. In this case, the maximum bar
reflectance is measured when the aperture is centered on the bar.
maximum space reflectance - the
maximum reflectance within any space.
message length - the number of
characters contained in a single encoded message.
minimum bar reflectance - the
minimum reflectance within any bar.
minimum reflectivity difference -
the difference between the smallest minimum space reflectance value and
the largest maximum bar reflectance value as measured across the entire
symbol.
multicode reader - also called an
auto-discrimination reader. A bar code reader processing the software or
firmware capable of decoding various types of barcodes. A switch
selectable, or firmware based, system permits the selection of the
desired code based on switch position.
multiple scanning/decoding/reads -
a technique employed within noncontact scanning and specifically moving
beam formats, which adds to the integrity of a symbol being read by
making two or more reads of the symbol and comparing the reads to ensure
agreement before the data is passed to a data processing system.
ominidirectional
- refers to a code format that can be read, regardless of orientation to
a give plane, such as a bullseye code, or a reader or scanner with the
ability to read a bar code symbol from any angle. The combination
of the mechanics of a supermarket checkout system slot scanner and the
UPC symbol permits omnidirectional reading as long as the barcode passes
over the scanner window. Many
omnidirectional scanners employ multiple x-axis and y-axis scan
patterns to achieve the omindirectional capability.
optical distortion - change in
appearance of objects when viewed through transparent material, adding
certain defects such as waviness of surface.
optical throw - the distance from the
face of the code reader or scanner to the beginning of the depth of
field.
orientation - the positioning of graphic
elements relative to a common reference, such as the base of a box,
bottle, or can; the alignment of bars and spaces to the scanner. Often
referred to as vertical, or picket fence, format or horizontal, or
stepladder format.
orientation bar - a code bar that
provides the barcode scanner with start and stop reading instructions,
as well as code orientation.
outer container - an exterior container
that provides protection to items of supply or unit packs for storage
and shipment. It may contain similar items or many different
items, as a multipak or repack. a unit pack sometimes serves as an
outer container.
photodiode array (linear) - the
grouping of many photodiodes, usually microminiature, in a line that
detects photon energy from the radiation that strikes a surface and
changes the reflected light into electrical current which can be
measured. Photodiode arrays are used in some barcode reading
devices which used in some bar code reading devices which detects
saturation (high reflection indicates a light space) and black current
(minimal reflection indications a dark bar). Each photodiode in
the array is sampled by a microprocessor, and the image of the bar code
is decoded by the microprocessor.
photodiode array (matrix) -
similar to a linear photodiode array, except having a height in excess
of one element, commonly referred to as a 64 x 64 array or a 128 by 128
array. Matrix arrays permit the viewing of more vertical area of a
barcode symbol permitting vertical redundancy, to average out localized
printing defects. Matrix arrays are less sensitive to changes in
element width sizes and acceleration through the symbol.
pitch - the rotation of a code
pattern about the x-axis; also called roll. The normal distance
between center lines or adjacent characters.
point-of-sale (POS) data entry system - a system in which actual
transactions are recorded by terminals operating on-line to a central
computer, such as supermarket cash registers and POS terminals.
These systems frequently employ optical scanning as a means of capturing
data.
portable data entry terminals -
PDET; a microprocessor-based, hand-held terminal capable of capturing
data by taking the data capture device to the product as opposed to
taking the product to the data capture device. PDETs can be either
batch oriented, where the data is captured remotely and later
transmitted to a computer, or an online device which immediately
transfers captured data to the computer through a radiofrequency (RF) or
microwave (MW) link. Features of PDETs include the number or
characteristics of data entry keys, the attachment of scanning
peripherals, program memory, data memory, the number of characters
displayed, the method of display, and data transmission techniques
presence sensor - a device, often
a photoelectric device, used in conveyor and transport systems to tell
the system that an item is in view and ready to be read.
quiet zone - the area immediately
preceding the start character and following the stop character which
contains no marking and is free of any extraneous marks; it is quiet in
terms of scanning signal produced. For example, the quiet zone of
a Code 39 Symbol is 10 times the width of the narrowest element or 0.250
inch, whichever is greater.
radio frequency (FR) / microwave (MW)
transponder - a technology of automated identification system that
operates on the same principle as security tags placed on clothing.
The tag signals an alarm if it passes through an antenna field, which is
usually located at the door of the establishment. Passive devices are
commercially available that will encode and transmit information back to
a computer system when in proximity of its associated antenna.
read area - area covered by a
scanner; especially important in material handling applications, such as
scanners reading cartons on a conveyor line. Bar codes must
reliably pass through the read area with the length of the symbol
parallel to the scan plane.
reader -
a device used for machine reading of bar codes; typically consists of a
scanner, a decoder, and a data communication interface.
reflectance - the amount of light
reflected from a surface; measured under specific conditions, in which a
surface coated with barium sulfate or magnesium oxide is considered to
be a perfect diffuse reflector of light.
reflectance, diffuse - reflected
light whose angle of reflection varies from the angle of incidence of
the illuminating light, such as in reflection from a rough surface.
resolution - in optics,
sharpness; the ability to reproduce fine detail; the ability of a
barcode scanner to read the narrow bars in bar codes. In printing,
a measurement of the narrowest bar that can be printed satisfactorily.
The measure of the ability of a lens, a photographic martial, or a
photographic system to distinguish detail under a specific condition.
The dimension of the smallest element dimension that can be
distinguished by a particular reading device. The measure of this
ability is normally expressed in width of aperture in mils, lines per
millimeter, or angular resolution.
reverse image - a symbol in which
the normally dark areas are represented by the material substrate and
the light areas are represented by the inked portion of the symbol.
RF scanner - that variety of
portable data entry terminals possessing the capability of
radio-frequency data link back to a computer system. Also called a
radio-frequency data terminal. The Bluetooth technology is being
widely used for RF scanner nowadays.
scan - the search for a symbol
which is to be optically recognized; a search for marks to be recognized
by the recognition unit of an optical s scanner. Movement of a
light source over a barcode and recognition of the reflective qualities
of the signal from that symbol.
scanner - a device that examines
a spatial pattern, one part after another, and generates analog or
digital signals corresponding to the pattern. Scanners are often
used in mark sensing, pattern recognition, character recognition and bar
code recognition. The scanner converts barcode symbols to
electrical signals for input to a barcode reader decoder for processing
and subsequent output through a data communications interface.
scanning/reading range - (also
called Operating range) the combined distance of optical ability of a
lens, a photographic material, or a photographic system to distinguish
detail under a specific condition. The dimension of the smallest
element that can be printed when employing a particular technique.
The narrowest element dimension that can be distinguished by a
particular reading device. The measure of this ability is normally
expressed in width of aperture in mils, lines per millimeter, or angular
resolution.
self-checking barcode - a bar
code that uses a checking algorithm which can be applied against each
character such that substitution errors can occur only if two or more
independent printing defects appear within a single character.
Checking at both the character and the message level greatly minimize
the probability of substitution errors.
Slot Scanner
or Slot Reader - the scanning portion of a
point-of-sale system embedded within the retail checkout lane counter.
Traditionally a helium neon laser is employed, reflecting the light beam
by a series of mirrors to create pattern which is recognized to read the
UPC symbol. The symbol is drawn across the scanner window so that
at least one beam of light intersects the entire UPC symbol. Also
called desk scanner or checkout scanner.
space - the lighter element of a
bar code formed by the background between the bards.
space
encoding
- in bar coding, the use of the spaces between the bars to carry
encoded in formation.
substrate - a foundation material
on the surface of which a substance is deposited, such as printing or
coating.
Symbol - a representation of something
by reason of relationship, association or convention . Referring to bar
codes, a combination of characters, including start/stop and check
characters, as required, which form a complete scannable entity.
Symbol density - the number of
characters per lineal inch; limited by the width of the narrowest bar or
spaces.
Symbol length - the length of the
symbol measured from the beginning to the quiet zone adjacent to the
start character to the end of the quiet zone adjacent to the stop
character.
Symbology - representation or expression
by means of symbols.
systematic errors - errors introduced by
the printer, reader or other system elements that are consistent for all
bars or all spaces
thermal printing - receipt
printers.
unidirectional code – a code format which
permits reading in only one direction.
Uniform Code Council – UCC (formerly known
as the Uniform Product Code Council-UCC); 8163 Old Yankee R., Suite J,
Dayton, OH 45459; the organization responsible for overseeing and
administering the Universal Product Code in the retail consumer
industry.
Uniform Container Symbol – UCS; a bar code
symbol designed for printing on corrugate board; a result of DSSG.
Universal Product Code – UPC; most
commonly a 12-digit bar code pattern adopted by the U.S. grocery
industry, which identifies the number system character (type of encoded
product), five-digit manufacturer number assigned by the UCC, five-digit
product code assigned by the manufacturer, and a modulo 10 check digit
as the 12th character, The code is numeric, and and there are
other versions. Version E accommodates six digits, and Version D is a 12
+ n-digit version. Nominal dimensions for the UPC symbol include a
module width of 13 mils (+) 4 mils. Magnification factors range
from 0.80 to 2.00 of nominal supporting densities of 10.21 to 4.08
character per inch, with a nominal of 8.17 characters per inch.
variable length code
– a code that can be of any length within a range of lengths, commonly
with a maximum length specified and frequently with a minimum length
also specified.
variable length filed – a data filed or
data element that may vary within a prescribed minimum and maximum.
variable length symbology – a symbology
whose format is not fixed beyond basic requirements for overhead
characters, such as start/stop codes. For example, UPC is a fixed
length, numeric symbology that supports only six characters (Version E)
or 10 characters (Version A). Code 39 is a variable length alphanumeric
code which can support any data length from one character up to a
maximum dictated by the reading system employed, typically not fewer
than 32 characters.
verification – the technical process by
which a symbol is evaluated to determine whether it meets the
specification for that specific symbol. Verification can be accomplished
by semiautomated means, with elements measured by a microscope and
contrast established by a densitometer. Verification can also be
accomplished by automatic means with a device that measures width of
elements, contrast, and reflectance, and establishes decodability.
Verifier – one whos
is responsible for the verification of a symbol; a device that performs
a dynamic analysis of a bar code symbol to ascertain whether the symbol
meets specifications. Diagnostic verifiers measure all parameters of the
symbol against the standard specification and details the variance from
the specification.
A
go/no go verifier performs a simple read of the code and tells if the
code is scannable with that light source, at that acceleration, and at
that angle of incidence.
Vertical bar code – a code pattern
presented in an orientation so that the overall coded area from start to
stop is perpendicular to the horizon. The individual bars are in an
array that looks like the rungs of a ladder.
vertical redundancy
– viewing an expanded vertical area of a bar code symbol to average out
localized printing defects, such as spots, voids, and bar edge
roughness. A feature of X&Y-axis moving beam readers and matrix arrays.
wand scanner – a hand-held scanning device
used as a contact bar code or OCR reader.
wavelength – the amount of space occupied
by the progression of an electromagnetic wave; a term describing the
frequency of light radiated by the scanners emitter.
Zero
suppression – the technique used to
shorten UPC codes by omitting certain zeroes from the bar code, If a
manufacturer’s number ends in 000 or 100 or 200, there are available
item numbers between 00000 and 00999 available. The six characters are
obtained from the first tow characters of the manufacturer’s number,
followed by the last three characters of the manufacturer’s number and
the third character of the manufacturer’s number, If a manufacturer’s
number ends in 300, 400, 500, 600, 700, 800, or 900, 100 item numbers
between 00000 and 00099 are available. The six characters are obtained
from the first three characters of the manufacturer’s number, followed
by the lat two characters of the item number, and ending with the number
3. If a manufacturer’s number ends in 10, 20, 30, 40 , 50 , 60, 70, 80,
or 90, the manufacturer has 10 item numbers between 00000 and 00009
available. The six characters are obtained from the first four
characters of the manufacturer’s number followed by the last character
of the item number, ending with the digit 4. If a manufacturer’s number
does not end in zero, then five item number between 00005 and 00009 are
available. The six characters are obtained from all five digits of the
manufacturer’s number, followed by the last character of the item
number. Zero suppression is the active coding structure for UPC Version
E.
