If you’re involved in purchasing barcodes you’ve probably heard of an ISO/ANSI score, but what exactly are these scores? And what do they mean? Here at Computype we want to make sure our customers understand what they are investing in and when it comes to ISO/ANSI scores, things can become a little bit tricky. An A-grade might be the best grade, but ironically it might not mean the best solution for your purposes. The goal of this discussion is to help you better understand what an ISO/ANSI score is, how it’s calculated, and what that might mean for your barcode solution.
What is ISO/ANSI and what is an ISO/ANSI barcode score?
ANSI is the acronym for The American National Standard Institute, an organization that develops systems of standardization for a wide array of products, services, and systems in the United States. Their goal is to improve the standard of living and the global competitiveness of US businesses through standardization, and so they created the ANSI barcode test. The ANSI barcode test was later taken over by the International Standards Organization (ISO), who stretches their goal of business standardization to a global level.
In their efforts to create norms and guidelines for businesses in nearly every sector, they have created a test and scoring system for barcodes. The ISO/ANSI barcode test is essentially a test of print quality. The quality of print is one of the biggest factors affecting barcode readability so it only makes sense that a test of symbol performance would focus on print quality. Simply put, the ISO/ANSI barcode score refers to the level of print quality of individual barcodes; however, print quality is only one of many factors that go into the readability and scannability of your barcodes.
How is the score calculated?
To those unfamiliar with the determining factors of high quality print and the environmental influencers that can impact the readability of barcodes, the scoring system can be difficult to decipher. This is why it’s important to understand how the test is run, how the scores are determined, and what they represent.
Lighting and scan speeds are controlled throughout the duration of the test. The barcodes are scanned as they run flat beneath a single-line scanner tethered above at a specific angle. As the codes are scanned they are tested on nine parameters of print quality:
1. Edge determination
2. Minimum reflectance
3. Minimum edge contrast
4. Symbol contrast
9. Quiet zones
The symbols are scanned a total of ten times and receive a grade for each scan on each parameter. Some parameters are scored on a pass or fail (A or F) basis, and others are scored on a scale from A-F.
Once the scores are gathered, the test device will look at each parameter, take the lowest of the ten scores received, and assign that score to that parameter. For example, a symbol that receives eight A’s, one B, and one C for Edge Determination gets a final score of C on that parameter.
The next step leads us to the overall score, and is calculated differently depending on the test operator. Most commonly the score is calculated by taking the lowest of the parameter scores and declaring that the overall score of the barcode. For example, if the barcode from before scored an A on every parameter other than edge determination it would receive a C-grade since the lowest scoring parameter was graded C.
Even though it is an uncommon approach, it should be mentioned that some test operators will average out the parameter grades. This means that if the same barcode from before was brought to a different facility where parameter scores are averaged it would receive an A-grade, a pretty dramatic difference. The method of averaging scores isn’t specifically mentioned in the ISO/ANSI barcode testing instructions, so it’s not as commonly used and more than likely your barcode provider is using the lowest parameter score as the final grade.
What does my score mean?
Imagine you’re back in school and it’s the beginning of a new semester. Your chemistry professor is describing the grading system for the class. This professor splits up your classwork into nine categories for grading: participation, essays, textbook assignments, journaling, in class activities, labs, quizzes, exams and presentations, there are ten assignments in each category. Say this professor grades each category based on the lowest scoring assignment of each category, then picks the lowest scoring category for your overall grade in the class. Would you drop the class?
I certainly would.
Why? A lot of reasons, one of them being that it doesn’t seem quite fair to be graded solely on my worst performing assignment. What if I wrote that horrible essay while pulling an all-nighter? Or maybe I’m just not a good public speaker. Receiving a grade based solely on your lowest point of performance can feel unfair.
Sure, barcodes aren’t college students but the grade received essentially reflects on the barcode’s lowest point of performance similar to that chemistry professors grading system.
In addition to the highly focused grading system, the test is performed under strict conditions that likely don’t apply to your work processes. A few ways the testing environment is likely to differ from your work environment include the scanner, the scanner orientation, re-scannability and lighting conditions. Your label supplier will need to know what these conditions are like in your facility so they can help you determine which range of grades will work with your processes.
Type of Scanner
The type of scanner used in the ISO/ANSI test is a single-line scanner. Although single-line scanners are still used today, they are used very rarely as more robust reading technologies have become widely available. Common scanning technologies like rastering scanners and CCD (photo) scanners compile several high quality images of a barcode in a single scan to create the highest level of readability even if the barcode itself is poor quality. These types of readers are often able to read F-scoring barcodes with little to no trouble. So, before requesting A-grade barcodes, ensure your reader requires high quality barcodes to perform, otherwise the investment may not be worth it.
The scan angle is controlled during the ISO/ANSI test, tethered above the barcodes the scanner remains at a consistent angle for the entirety of the test. This is great for consistency in a test, however it’s not how your processes likely run (unless you’re using automation, which we will get to). In most real-life cases the scan angle can be adjusted and the label rescanned if the original scan angle was not acceptable. In the case of automation, though the scan angle is fixed and the label can’t be rescanned unless removed and scanned by hand, the scanner within the automation equipment isn’t likely to be a single-line scanner making it less likely to require rescanning due to poor scan angle.
An environmental factor which is highly controlled during the ISO/ANSI barcode test is lighting. Even if lighting is controlled in your facility it’s unlikely to be set to the same specifications the ISO/ANSI test requires. Light levels affect the readability of barcodes by obscuring the contrast through reflection and shadow; in your facility you are likely able to make adjustments to the lighting, move barcodes into better lighting or have access to high quality scanners that can work under poor lighting conditions.
Although it’s far from ideal, we mentioned that in most real-world scenarios there is an opportunity to re-scan the barcode label. Even with automation the labeled object can be removed and scanned with a hand scanner or placed back in line to be scanned again. Rescanning is far from desirable and with proper scanning equipment, lighting and a good scan angle it can typically be avoided completely.
During the ISO/ANSI test the barcodes are scanned a total of ten times, however, the lowest of those scores becomes the overall barcode grade, reflecting on the worst-case scanning scenario while excluding any positive results. This could mean the barcode was read on the first, second, and third scan, maybe it only misread on the seventh scan. Essentially the ISO/ANSI score can’t tell you exactly how likely it is your barcode will read on the first scan with all factors in mind; in fact in most cases it’s more likely your barcode will read on the first scan than the test results will reflect.
Unless your facility is scanning barcodes under the same exact conditions as the ISO/ANSI test there are a lot of opportunities to improve the readability of your barcodes after they’ve been printed. In most cases your facility is already set up with these opportunities to improve readability. It’s very likely your facility is using either a rastering or CCD scanner and your operators have the ability to adjust lighting, modify scan angles or rescan if something goes wrong.
The ISO/ANSI score does serve the purpose of providing proof of the print quality of barcodes, and print quality is a major determining factor of readability. But the ISO/ANSI barcode grade doesn’t necessarily reflect on the readability of your barcode as a whole. There are many more factors that go into how readable your barcodes will be in real-world applications. In some cases barcodes aren’t even able to grade above a C due to the inks, substrates or laminates used in making them, but they are able to scan consistently with the right tools and environment.
If you’re working with a reputable barcode label supplier and manufacturer you can rely on them to provide quality products. What is most important is not the ISO/ANSI grade of your barcodes, but that your barcode supplier is interested in learning about your processes so they can help you to assess your needs and find the best solution.