As with most wording in any technical capacity, when we talk about barcodes, it can get a little ‘tech-speak’ which often seems as ‘clear as mud’. Here at Computype, barcodes are our business and expertise. Because we realise not everyone is behind the scenes or knows the technology as we do, we have listed a few definitions to help makes things a bit clearer:
the black and white bars or the ‘guts’ that make up a barcode. Elements that make up a barcode may include the following: stop and start symbologies (the beginning and end indicators), quiet zones, interpretation line (the line of characters – typically consisting of numbers – that are human-readable, below the barcode), space/bar patterns (the widths of the bars and spaces), inter-character gap (used to separate characters), code density, ratio and X dimension.
The width of the narrowest element (black or white bar) in the barcode. This determines the remaining spaces and bar widths as well as the length of the barcode itself. The smaller the width of the X dimension, the smaller the total width of the barcode - making the barcode a high-density barcode that is more difficult to scan and print. The larger the width of the X dimension and barcode means a more consistent readability and more reliable barcode printing or a low-density barcode.
The relationship between wide and narrow element widths – 2:1 or 3:1, for instance. The ratio plays a part in determining the barcode’s density. This is important in terms of determining what type of scanning device will be used to read the barcode – higher density barcodes need high-performance scanners.
The amount of space a bar or gap takes up, measured in Xs. A narrow bar might be 1X – one module; a medium width bar could be 2X and therefore take up two modules. This is sometimes referred to as the X dimension; however, in terms of wider spaces and bars, the module is considered multiples of this thin bar.
The amount of characters that can fit in one linear inch (cpi). Such variables as the ratio of the elements of narrow to wide, the barcode’s symbology (the type of code), or the X dimension (the narrowest width of the barcode), may affect the barcode density. The higher the density, the more difficult the barcode is to read and therefore in need of a high-performance scanner.
A verification term meaning the exact intended value and size for a specific parameter. To have a nominal value, cases must be categorized into groups (unordered) in which, the following is required of the groups: a) all cases must be covered by the group (all-inclusive), and b) each individual case is required to belong to one group only (mutually exclusive).
In discrete symbologies, tolerances are quantified as + or – deviations from the nominal. With first-time readability rates at an extreme high, this alone, can attest to a barcode’s reliability. A quiet zone violation would be considered a barcode tolerance failure’s most common culprit.
The blank margin on either side of the barcode which tells the reader where the code starts and stops. The quiet zone is usually ten times the width of the narrowest element, or ¼ of an inch, whichever is greater. If the space of this area is too short, the barcode will become unreadable.
Along message broken up into multiple shorter barcodes. This is helpful when the overall message is long, or if there’s a need to create two barcodes side by side, with one functioning as a security check. Blood banks use concatenation for scanning DIN and ABO, product code and expiry dates.
We know the technology of barcoding inside-out, and while barcodes are all about lines and spaces, there are definitely no gaps in our knowledge. We appreciate there’s a lot to take in with barcoding, so if you have any questions don’t hesitate to get in touch with us.