How to Verify a Barcode
Verifying a barcode may be more complicated than you think. It is more than a scanner. You don’t just get a verifier and press the button. It begins with getting the right verifier—they are not all the same.
To begin with, make sure you have an ISO compliant verifier. Surprising as it may seem, not all barcode verifiers comply with the ISO specification as a test instrument. This can be confusing since most verifiers use some or all of the ISO specification for barcode quality to report the verification results. But that is not the same as compliance of the verifier itself. Confirm that the verifier complies with ISO 15426 as a test device. Then make sure it tests barcodes to their ISO print quality standard: 15415 (for 2D symbols) and/or ISO 15416 for 1D barcodes. Unclear or evasive language in the verifier data sheet signals that it is not an ISO compliant barcode test device.
Next, make sure your verifier has been recently certified for ISO compliance. Re-certification is usually done at the factory, although you can purchase a set of test cards with known errors built in to test the verifier performance. If your ISO certification will allow you to self-certify a test device, this can be a great convenience and time-saver.
Now you are ready to verify a barcode. What are you testing for? The simple answer is “…anything and everything that represents risk with your trading partners in your supply chain.” If print quality is the only concern, test just for that. Increasingly, data structure is also a concern. You may need to configure your verifier to test for data structure. For example, should your barcodes be compliant to the GS1 General Specification, or to the GS1 Healthcare specification? Or maybe the HIBCC spec? It’s important to know and set the verifier accordingly—and here again, not all verifiers have the ability to teste more than print quality. Be a smart buyer. Verifiers are risk management tools; price should enter in the buying decision only after you know you are buying the right tool.
Believe it or not, even after you have considered all these factors, there are still things most verifiers don’t test for. One of them is whether or not the human readables (usually) beneath the barcode match the data encoded in the barcode. The only way to test for that is to visually compare the human readables next to the barcode to the readout of symbol data on the verification report. A mismatch is a rare but devastating—and not impossible—occurrence.
In the ISO system, the final grade in the verification report is the lowest grade for any one ISO parameter. That is the parameter to monitor and control over time, during a print run. If that one parameter degrades, the final symbol grade will degrade. If you verify a barcode at regular intervals during a print run, your diligence can prevent that from happening. You can even predict when a failure will take place based on the rate of deterioration during a print run, and thereby take steps to prevent that eventuality.