How Does Barcode Verifier Grade Relate to Scanning?
What does the verifier grade mean regarding scanning? Does an A grade guarantee scanning success? Does an F grade guarantee scanning failure?
We wrote on this topic a while ago, and although the basics haven’t changed yet, they are about to. But first, regarding that loaded term “guarantee” didn’t your mother tell you, there are no guarantees?
“If there are no guarantees, why did I buy a verifier?” you ask non-rhetorically. You bought a verifier so that you could establish a benchmark which you could hold up to anyone questioning your barcodes. Don’t forget, everything is a sequence of events, whether it is a supply chain, a packaging line, a sortation system or whatever. You use a verifier in order to nail down your part of the sequence of events. Your ISO compliant verifier measures and grades your barcodes to a much tighter standard than scanners that just read them—but scanners are also made to standards. But scanner standard are looser than verifier standards. That’s why scanners are ineffective as verifiers. And that’s also why a verification report on your barcodes is an important benchmark.
The verifier grade for your barcodes is a C but your customer says they don’t scan. This is possible but unlikely, and the most probably cause is, your customer’s scanner is malfunctioning. It may be damaged of it may be nearing the end of its useful life because it is worn out. If it is unable to reliably scan your C grade barcodes, chances are it is out of spec and ready to be replaced. While the verification report is not a guarantee, it is a powerful piece of evidence that you want in your arsenal.
If there are no guarantees, what does a verifier grade A actually mean? It means the barcode is likely to scan successful on the first try. Some percentage of A grade barcodes will need to be scanned a second time, but most of them will decode the first time. Why can’t an A grade be a more solid assurance of scanning success? Because scanner standards are relatively lenient and don’t forget, there are very different scanner technologies out there: lasers, linear imagers, cameras and even smart phone cameras. And there are very different scanner configurations—slot scanners looking sideways, counter mounted scanners looking up, hand held scanners looking who knows which way. And there is a whole world full of different ambient lighting situations that influence the way each scanner performs—and don’t forget, ambient lighting could change if the scanner is near a window (what front line scanner is not near a window?).
A verifier grade F does not “guarantee” a barcode will fail everywhere it goes, but don’t defend your F grade barcodes based on that argument. The whole point of the barcode quality grading system is not to support a system of guarantees—it is to find a way to express the predictability of barcode performance regardless of where it goes and what type of scanner it encounters regardless of its technology, its age and condition, and whether it is a rainy spring morning or a blazing bright, sunny winter afternoon.
Incidentally, your verifier is a reliable benchmark only if it is an ISO compliant device that has been recently calibrated and certified. Reflectance calibration is something you can do with a NIST-traceable calibration card available from the manufacturer. You should recalibrate at least once a month. ISO compliance certification is also available from your verifier manufacturer, assuming you bought an ISO compliant verifier. Buyer beware—not all verifiers are ISO compliant.