Introduction to Barcoding
Why you should use barcodes
The automatic identification industry has played a key role in the advancement of identification technology.With its primary focus on capturing information both quickly and accurately, automatic identification provides the fastest and most efficient means of gathering data. Barcodes can also be produced easily and inexpensively. They can be printed on most dot-matrix, laser, and thermal transfer printers depending on the quality you demand. A minimum setup of a dot-matrix printer and a wand produces acceptable results.
All Barcode Systems
All barcode system needs can be determined by asking two questions, (1) how and where will you print the barcodes, and (2) how and where will you read them. The following pages will help you answer those questions. Call our sales consultants to discuss your specific application.
Contact scanners require physical contact with the barcode. Non-contact scanners can read barcodes from a distance. General purpose laser scanners can read barcodes from a distance of 4 inches to 18 inches away. High performance scanners can read barcodes from 7 inches to a distance of 20 feet.
Symbologies and Resolution
A barcode is a message that holds information. The structure of the barcode consists of the height and the width. Information is encoded into spaces and bars of various width. The height of the barcode does not hold any information. Using the height, however, you can enlarge a barcode for easy scanning or for better visibility. The number of characters are represented in a linear inch called the barcode density. The density depends on the symbology. For example, using Code 39, 9.4 characters can fit in one inch. When using Interleaved 2 of 5, 17.8 characters can fit in one inch.
The resolution of a barcode is dependent on the narrowest element of a barcode (X dimension), and can vary from high resolution: nominally less than 0.009 in. (0.23 mm), medium resolution: between 0.009 in. (0.23 mm) and 0.020 in. (0.50 mm), and low resolution: greater than 0.020in. (0.50 mm). Currently there are more than 400 barcode symbologies in use. Some are alphanumeric, while others contain the full ASCII set, or only numeric data. Only 10 are standarized and prevalent in industry. Here are four examples of some popular barcodes:
Code 3 of 9
Code 39 is the most widely used barcode. It is an alphanumeric code, which supports both numbers and capital letters. The barcode has a total of 9 elements, 5 bars, and 4 spaces for each barcode character. Code 39 is used for shipping departments and product descriptions.
UPC,UPC consistes of the following subsets:
UPC-A: UPC-A is a barcode used to encode a 12 digit number. The digits are arranged in the following manner: The first digit is the number system character, the following ten digits are the data characters, and the final digit is the checksum character. UPC-A is used by grocery stores within the United States.
UPC-E: UPC-E is the smallest barcode available because it is a zero suppressed version of the UPC-A barcode. The data characters and the checksum characters are all condensed into six characters. UPC-E is used with the small EAN-8 bar code, has two country characters (which identify the country of origin), 5 data characters, and a checksum character. The EAN-8 is used for applications overseas.
EAN-13: EAN-13 has two country characters, ten data characters, and a checksum character. Thus, EAN-13 encodes 13 characters. The EAN-13 is mostly used in grocery stores in Europe.
Interleaved 2 of 5: Interleaved 2 of 5 is a numeric code only. There are five elements to each character, two wide and three narrow. This code is also capable of having from 2 to 30 digits. It also requires an even number of digits to be encoded.
Code 128: Code 128 is used for all numeric bar codes or alphanumeric barcodes. It is also a high density bar code which can encode the entire 128 ASCII character set. It is also capable of encoding two numbers into one character width, called double density.
UCC-128: UCC-128 is a subset of Code 128. It is a 19 digit fixed length bar code which uses the double density numeric Code 128 C to create the bar code. The UCC-128 is often used for shipping containers.