Barcode verification is typically used in supply chain applications and by retailers worldwide and is carried out using barcode verifiers that examine factors such as symbol contrast, minimum reflectance, decodability and defects in comparison to ISO or other industry standards and specifications. This enables any trading partner in a supply chain to test for barcode quality and ensure that they have a low error rate.
Failure to supply consistently reliable barcodes can result in large penalties and loss of revenue for label or package printers, and even to the loss of a customer or barcode printing business. Inconsistencies in barcode quality in the production or processing chain can lead to process inefficiencies and downtime, unreadable barcodes needing to re-labeled or to re-scanning.
Every time a barcode fails to scan it will also incur lost time, productivity and costs for a retailer, either through the time taken in having to input the information manually at the checkout, or maybe in the rejection of deliveries.
On this basis, barcode verification should be a normal and acceptable part of a printer’s QA system. But how is it carried out?
A barcode verifier is normally available as a desktop, fixed position or portable device which enables precise measurements to be taken of each individual bar and space in a code, as well as measuring the amount of light reflected from each barcode module. They are different from barcode scanners in that they are not solely concerned with reading the barcode, but rather in the quality of the print itself, ensuring that the printing of the barcode is of a quality for consistent reading.
Figure 6.1 - Portable device being used at Mercian Labels to ensure barcodes meet performance requirements
Like most barcode scanners, barcode verifiers still read a narrow path through the barcode and convert the reflected light into what is known as a Scan Reflectance Profile in which dark bars are represented by troughs and the white spaces represented by peaks. The barcode verifier then analyzes this data to provide information about the barcode’s quality.
Devices may be a simple spot checking mobile device or integrated into the printing process itself. A proper verification system will provide the insurance that barcodes will scan at every level of the supply chain for increased efficiency and smooth customer/supplier relations.
Depending on the sophistication of the device, the verifier may automatically identify the symbology and the magnification, measure the print quality to ensure it can be read by even the most basic scanners in a range of environments, check the structure of the data and then validate the content, and confirm the printed barcode matches any specific standards that ned to be met, such as ISO/IEC 154426, ANSO or CEN.
It will also provide diagnostic information so that any problem can be identified and any necessary corrective action can be undertaken.
Most barcode verifiers will check for:
Barcode or reading defects
Some of the more advanced verification devices may also be able to check magnification, bar ratios, data validity, application standards or data format.
There are a number of different types of barcode verifiers depending on whether they need to be mobile or fixed, off-line or on-line.
The most commonly used verification solutions used by the label and packaging printing sectors are:
Hand-held verifiers, which are available as mobile devices that will have a built-in scanner and a small display that will provide a grading for the code. They are used to spot check barcodes after printing and will offer either a printed or downloadable report of the code that is being verified.
Figure 6.2 - An Integra 9580 handheld linear and 2D barcode verifier
PC-based verifiers. These are easy to operate and will use PC-based software to aid verification and to present the results data. They are deemed to be best suited for small linear barcodes and basic applications.
Portable verifiers are more suited to the more robust types of applications. They are fully portable (see the LVS verifier in Figure 6.3), easy to carry, extremely durable and can be set up for a wide range of commercial uses. Logged data files can either be downloaded at a later stage or, if required, viewed on the device directly by the equipment user.
Figure 6.3 - Use of an LVS Integra portable verifier for off-line barcode verification in multi-line production environments and warehouses
The latest portable verifiers support the current ISO, UDI and GS1 regulations and can verify barcoded labels on a variety of surfaces, including metal, shipping containers, corrugated boxes and cases.
On-line verifiers are high-speed production line systems and are ideally best suited to industrial level applications, including product labels for mass production items. On-line verifiers can have a scan rate of up to 150 scans per second and can be mounted in front of, and directly connected to, a barcode printer to check each barcode as it is produced.
These devices allow operators to automatically arrange for the reprinting of poorly made barcodes at the printer level . or to even stop printing if continued poor quality barcodes are being produced. They are best suited for high volume print applications where spot checking is not feasible.
Figure 6.4 - Optical character verification, 2D and barcode reading, quality checking and matching at speeds up to 4 meters per second with the Sick Lector
THE VERIFICATION PROCESS
Quality control and the necessary production staff will need to be trained in the verification process and in the use of barcode verification equipment.
In use, each barcode symbol should be checked to ensure that the bars are the correct height, and that no horizontal lines or spaces cut through the symbol. Any marks crossing the bars and spaces of a symbol will undoubtedly reduce its effective height and make it much more difficult to scan.
In relation to the barcode in use, the position of the barcode on the packaging will also need to be checked to see that it meets the relevant EAN/UCC specifications. Any final labeling or wrapping should additionally be examined to ensure that the bar codes remain visible and scannable.
When checking barcode symbol quality, it is generally advisable to simulate the final, filled product or package.
If, for example, a white background is printed on to a clear substrate, then the color of the contents of the item should be checked. If it is not possible to simulate the contents, verify the barcode twice, once over a black background and then secondly over a white background. The poorer of the two grades will provide information about the worst possibility.
Having checked that the barcodes are in the correct position and are not shortened in height (truncated), the necessary barcode verification equipment can then be used to provide an overall grade for each symbol.
It should be noted that there are also barcode verifiers that are capable of verifying invisible 2D codes used in anti-counterfeiting and security applications. The codes are visible under UV light, as can be seen in Figure 6.5, using a TruCheck 2D UV barcode verifier.
The verifier is operated by Webscan’s easy-to-use software interface which can verify both linear and 2D barcodes.
Figure 6.5 - Webscan’s TruCheck 2D UV verifier
BENEFITS OF BARCODE VERIFICATION SYSTEMS
The use of automated barcode systems, whether at scanning checkouts, in warehousing, storage and distribution, in manufacturing and industrial applications, in the automotive or aerospace sectors, continues to grow rapidly and becomes more and more widespread every year.
Without reliable and accurate barcode print quality that works effectively, scans first time, and provides the correct data, these automated systems would be of little benefit.
Barcode verifiers are therefore used to enable the label and package printer to guarantee the barcode printing, the barcode quality and the barcode data on the barcoded label or pack that is being supplied.
Barcode verification enables the label supplier to maximize the efficiency of their manufacturing process; to comply with symbol quality industry standards and directives, to minimize the return of faulty barcoded labels; to offer real-time quality control with verification of the barcode printer or printed output; and, at the end of the job, increase customer confidence and satisfaction , something that cannot be done with eye alone or even with a standard barcode scanner.
Barcode verification is an essential requirement that helps to ensure that barcodes read accurately first time and every time.