Barcode Verifier Validation: Part 2
Recently we wrote about how to make sure your barcode verifier is accurate, by using a Performance Qualification test kit. The PQ test kit is a card deck of precise images, each displaying an engineered, calibrated error. If your verifier detects the error and reports it within its tolerance, you can self-recertify your verifier as compliant to the ISO standard.
Although not as accurate or elegant as a PQ test kit, there are other things you can do to confirm the accuracy of your verifier. Here are some simple steps to ensure your barcode verifier is performing optimally:
• Confirm that your verification software is the latest version. Visit the verifier manufacturer’s website to see if software updates are available for download and installation. Each update should have a complete list of what the update includes, from bug fixes to changes in the standards, new features and capabilities. This does not optimize the device’s operational accuracy, but it does ensure that the software is up to date.
• A more accurate way to gauge verifier performance is to purchase a Certified Calibrated Standard Test Card (CCSTC), available from GS1 or Applied Image, Inc. These are less expensive than a PQ test kit but definitely not cheap.
• A quick and easy test is reflectance accuracy. Reflectance is the basic technology behind barcode scanning. Therefore, accurately detecting the maximum and minimum reflectance values is very important. Reflectance calibration cards are readily available and relatively cheap, compared to PQ test cards or CCSTC’s.
• Find and archive a known benchmark barcode. Ideally this would be a perfect symbol that achieves a high grade on all of the ISO parameters, for the simple reason that it is easy to remember what those grades should be—all A’s. However, it could also be a less-than-perfect symbol with one or more parameters reporting lower grades. What is important is that you know what those grades should be. If your verifier repeats those known grades, all is probably well.
How do you know what those grades should be? Ideally, they were tested and graded with a lab-standard verifier but even if they originated with your own verifier—for example when it was new—what you are determining by retesting them is that your verifier is performing uniformly. If it returns a different grade, something has changed, and it is probably not the barcode.
It is easy to lose sight of the “big picture” with a very specific quality assurance function like verifying barcodes. You do it for a variety of reasons. The largest, most encompassing reason is risk management. Bad barcodes can do a lot of damage. If you have a barcode verifier, take a few simple steps to make sure it is working right. We can help.