Codabar is primarily
used by U.S. blood banks, photo labs, and FedEx airbills.
Codabar being a self-checking symbology, has a very low error rate (1 in 9 million). Its high printing tolerance makes it ideal for the packaging industry. Plus, Codabar is relatively simple to design and use.
Codabar uses a six digit identifier for each unit of blood, these six digits are not enough to
identify every unit of blood collected worldwide.
Which is a concern where blood is processed or tested centrally, or transferred across regional or national boundaries.
Codabar is a variable-length, self-checking, two-width, discrete symbology. Since Codabar is self-checking, there is no established checksum digit. Codabar encodes characters using two different width of bars and spaces. A wide bar or space is three bits wide, whereas a narrow bar or space is one bit wide.
Structure of Codabar in Libraries
A barcode beginning with “2” denotes a patron number; one with a “3” denotes an item. The next four digits are unique library identification code. The next eight numbers are the item or patron number followed by check digit number. This scheme can handle 10,000 separate library systems, each with million items and million patrons.
Structure of Codabar in Blood Banks
Each blood donation is assigned a 6-digit unique identifier (donation number) and is issued with a set of identical Codabar barcode labels representing this donation number. The donation number is included on all paper work and computer records.
One can use Label Flow™ barcode software for printing barcode labels with codabar barcodes or use Asset Track (asset tracking software) for labeling and tracking blood bank samples, photo labs supplies, and shipping bills.