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By Paul Yarnell

Bar codes are designed to make life easier for everyone but a badly printed bar code is worse than no bar code at all. It is unwise, therefore, to print bar codes without verification on items such packaging, certificates, covers and labels, especially if they are destined for use in the supply chain. Fortunately, there now is a choice of efficient and reliable bar code verifiers available at economic prices. Using a verifier as an integral part of in-house quality assurance procedures will probably recoup the investment within months and continue to save money from then on.

The importance of quality in bar code printing was emphasised recently in a report, "Barcoding – Recommendations for Best Practice" prepared by MR BIG and available from the Institute for Grocery Distribution (tel. 01923 857141). MR BIG is the Major Retailers Barcode Integrity Group and includes many household names. The report seeks to achieve a "good scan every scan" and states "it is essential that printers and suppliers verify the quality of their barcode symbols". Increasingly retailers and their distributors reject goods where the bar codes do not scan efficiently, or they may impose charges on the supplier.

Changes and developments in artwork, printing and in materials mean preparing a bar code by a specified process is no longer adequate. For example, a higher recycled content in card will decrease contrast. Verification is the only practical answer for checking the quality of codes.

Verifiers look much like standard bar code readers. In reality they are significantly more complex and gather and analyse far more data, which is why they may seem slower. Checking bar codes simply by scanning with a standard bar code reader is not sufficient. The crucial difference is that a verifier is a measuring device not a reader and only a verifier can be used effectively as a quality control instrument.

The current generation of verifiers has brought prices to an economic level, with effective equipment available from around £1000 up to £8000, depending on the levels of complexity and performance needed. It is important when selecting a verifier to check that it will give full CEN-ANSI-ISO standards verifications. It should be able to read the full set of symbologies you are likely to encounter. These may include EAN 8, EAN 13 and EAN 128, Code 128, UPC A and E, Code 39, Codabar and Interleaved 2 of 5. Ideally, the verifier will distinguish between these automatically. Equally important, the supplier of the verifier should be able to supply software and hardware updates that will keep the equipment up to current requirements, without the need to invest in a complete new system.

When a verifier checks a code it examines a range of features such as the dimensions, wide-to-narrow ratios, light margins, reflectance, symbol and edge contrast, modulation, check characters and decoding. If there are problems, or if any of these are nearing the limits of acceptability, they are identified and indicated.

Several current verifiers also offer the option of product look up, which means you can check that the bar code printed represents the associated product. Another useful feature is some form of data storage, especially where ISO 9000 series quality standards are in force, as these keep a record of what checks were made, when and with what results. In April this year, Label Vision has added a further option which should be of particular relevance to printers – a verifier portable display unit. In setting up, a printed sample can be taken to the verifier and the bar code put through the full verification procedure. During the run, at the machine, codes can be checked frequently using the portable display to alert operators if any aspect of the code is drifting towards a limit. Corrective action can be taken before the problem becomes a cost.

Product Information:
LVS 900 Data Sheet (requires Adobe Acrobat Reader)
LVS 9000 Data Sheet (requires Adobe Acrobat Reader)
LVS 6000 Data Sheet (requires Adobe Acrobat Reader)

More information:
Label Vision Systems, Inc.
101 Auburn Court
Peachtree City, GA 30269
1-800-432-9430
+1 770-487-6414
www.lvs-inc.com