Frequently Asked Questions (FAQ) | Barcode Verifiers

What is barcode verification?
Barcode verification checks barcode quality and scanability by examining the optical characteristics of the code according to industry standards and specifications, based upon the ways that actual barcode scanners work. Barcode verification standards are set by international organizations (such as ISO) and industry groups (such as GS1 or HIBCC). Barcode verification is designed to be predictive of scanning success and is the only way to ensure 100% scanability.

Why verify?
Quality control
A barcode not scanning correctly can have serious effects ranging from manufacturing errors to production downtime. Verification gives you feedback about your barcode production process that you can use to control the process itself. Successful verification results ensure that a label or direct part marker is working properly and will be readable further on in the supply chain.

Contract and Industry Compliance
Many government agencies (such as the US FDA and DOD) and large retailers require barcodes that conform to industry standards. The only way to certify compliance to these standards is to demonstrate barcode quality through verification. Some industries require verification to a specific standard (typically an ISO standard).

Customer Satisfaction
Verification guarantees a first-time scan rate. Correctly scanning barcodes will prevent fines from major retailers or production downtime. When barcodes do not scan correctly, the data has to be manually entered, opening up room for human error.

Why can’t I just use a scanner to verify my barcodes?

A scanner is designed just to read the barcode. Just because your scanner can read the barcode does not ensure that it will be read by other scanners. It only means that one area of the barcode is readable by that particular device.

Verifiers are precise instruments that determine the quality of the barcode through decoding, measuring, and checking the format of the code. Unlike scanners, true verifiers measure the characteristics of a barcode to industry standards such as ANSI X3.182, ISO/IEC 15415, ISO/IEC 15416. The best barcode verifiers are accurate to ISO/IEC 15426-1 and 15426-2 standards. Verifiers will analyze how well the barcode will perform in different environments based on international standards. It will indicate where the barcode is deficient so corrective action may take place.

If you are responsible for delivering readable, in-spec barcodes, then the only way to ensure that the barcodes function properly is with true barcode verification.

Why won’t my barcode scan?
There are many things that prevent a barcode from scanning. Even the best printers can produce improperly formatted and/or unreadable barcodes. Ribbon wrinkles, blown printer heads, and incorrect heat settings can cause a thermal printer to malfunction. Laser printers may be using too much or too little toner, leading to bar width growth problems. The barcode may even be formatted incorrectly, independent of printer problems and thus not conform to data format conventions such as those specified by GS1.

A verifier can prevent bad barcodes by recognizing and diagnosing the problem areas before they become a problem further down the distribution channel.

Will verifying save my company money?

Barcode verification can save your company serious money by preventing chargebacks. According to the National Chargebacks Management Group (NCMG), these fees typically reduce a manufacture’s overall revenue by 2% to 10%. Major retailers, such as Walmart, are known for issuing costly chargebacks when items delivered do not meet expectations. TESCO is another company with large fees. This retailer fines £40,000 per incident and returns the merchandise back at the manufacturer’s expense. Barcode verification will ensure that merchandise will not be sent back because of unreadable barcode symbols.

Verifying can also ensure that your mobile barcode campaign is properly implemented. A recent study by GS1 UK and Cranfield School of Management discovered that 91% of mobile barcode scans return incorrect product descriptions. Save your company money from having to re-do a marketing campaign due to improperly printed codes.

What are the variables that a verifier will test?
The parameters that are measured depend upon the symbology. Verifiers for 1D linear barcodes should test 9 quality parameters according to ISO/ANSI specification. These are:

1) Edge Determination

2) Minimum Reflectance

3) Symbol Contrast

4) Minimum Edge Contrast

5) Modulation

6) Defects

7) Decode

8 ) Decodability

9) Quiet Zone

For more information, see the complete description of the ANSI/ISO Quality Parameters.

For multi-row stacked barcodes, the process is similar and the parameters are the same, except that these parameters will be measured on each row of the symbol. Furthermore, if the stacked symbol contains error correction (for example PDF 417 but not GS1 DataBar) then Unused Error Correction will be included.

For 2D matrix symbols, several parameters are different. These are:

1) Unused Error Correction

2) Fixed (finder) Pattern Damage

3) Grid Non-uniformity

4) Axial Non-uniformity

The parameters for symbol contrast and modulation are similar to the parameters for 1D linear codes, except that the computation of the grade for Modulation is different in that it takes into account the availability of error correction in the 2D symbol.

What is MinQZ?

This is the size of the “quiet zone” on the left and right sides of the barcode. There is a minimum required blank space on either side. If you’re receiving less than a passing grade there is probably some printed graphics or the edge of the label itself that is too close to one end of the barcode.

What is the difference between scan grade and overall symbol grade?
The scan grade is the result of a single scan along one point of the barcode. The overall symbol grade is the average of each scan grade. According to ISO/ANSI standards, barcode verification requires 10-scans spaced evenly throughout the code.

What should I do if my symbols are receiving failing grades?

When verification software reports that the symbol failed, the user can view a full detailed report. Each of the 10 individual scans’ results will be displayed and graded on each parameter.

From here you can analyze on which parameters the barcode failed, and how to fix the problem for subsequent print runs.

Refer to ANSI/ISO Quality Parameters for a complete understanding of the cause of low grades for each parameter. Based on the particular parameter that caused the failure, you can adjust your production process to improve that characteristic of the barcode.

Why would a barcode fail a verifier test but still scan?

Barcode scanners are extremely aggressive at reading poorly printed barcodes. However, a poorly printed barcode may scan on one type of scanner but not on others. Barcode verifiers measure the code quality against a set of standards. If a barcode passes a verifier test, the barcode will be able to be read on any scanner, regardless of when it was manufactured.

However, there are cases where a failed barcode may still scan. The barcode scanner may be the most cutting-edge one available and can still scan despite barcode quality issues. This still remains a quality issue further down the supply chain. With different scanners, lighting, and human operators, the barcode that failed the verifier test may not scan in the future.

I have a low-cost verifier and a barcode passes my verifier tests, but a customer says that the barcode fails his verifier tests. What is happening?

A low-cost verifier may have been low cost because it is out of date with current standards. Your customer is probably using an ANSI standard verifier while your low-cost verifier might be utilizing traditional standards.

It may be time to purchase a newer verifier that is up-to-date with all the latest industry and international standards. Let Webscan’s resellers assist you in choosing the right one for your company.

What is the difference between verification and validation?

Verification and validation are two distinct processes. Validation merely checks that the barcode will scan on one specific barcode reader, at one particular angle and at one particular time. It also will check if the decoded numbers are correct. Just because the barcode scans properly with one scanner does not guarantee that it will work with other scanners down the supply chain. Human readability may also be checked during barcode validation.

Verification differs in the fact that it examines the optical characteristics of the barcode compared to international and industry standards. The barcode is then given a pass or fail grade based on these parameters. Diagnostic information lets the operator know what defects may exist in the barcode, which can help to correct the printing process. Barcode verification is required for many industries and will ensure 100% scanability.

What is a Scan Reflectance Profile (SRP)?

A Scan Reflectance Profile illustrates the analog signal of a single line across the entire width of the code. It is recorded by the verifier in a reflectance graph and analyzed by specific parameters (Symbol Contrast, Defects, Modulation, Edge Contrast, Maximum and Minimum Reflection, Bar Width Gain/Loss, and Decodability). Each of these parameters will either receive a pass, fail, or letter grade as per the requirements in the ANSI document.

Where can I find more information about ISO/industry standards for my barcoding needs?

How can I get a barcode number for my product?
GS1 (Global Standards One) is an international non-profit that provides UPC and EAN barcodes. Here you can register your company to receive a company prefix, assign identification numbers to products, and begin to use barcoding in your business operations.

Where can I find a glossary of barcode terms?

Our Barcode Glossary contains helpful barcoding and symbology terminology.

What is the current version of the TruCheck software?

Version, 3.03.66 Click this link to download the latest version.

Software can also be downloaded on https://support.cognex.com/en/downloads/webscan

Product Questions

I need to verifier both 1D and 2D barcodes. What verifiers can do both?
The TruCheck Optima and TruCheck Omni are both great solutions for verifying linear and 2D barcodes. For online high-speed verification of matrix symbologies, TruCheck Inline is a great choice.

Feel free to contact one of our reseller partners for more help in choosing the appropriate verifier for your business needs.
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What verifiers will offer a letter grade?

All of Webscan’s barcode verifiers offer ISO grading. Visit our Products page for more information.

How can I keep records of verifier data?
Keeping record of barcode verification for industry compliance has never been easier. Webscan’s PC-based units allow verification data to be saved as a PDF, HTML file, or exported into an Excel spreadsheet.

Want to keep your records all in the same place? Simply change the settings to append a PDF document and have all the verifications from one job as pages in a singular file.

Pharmacode should be turned off when you are scanning UPC codes. In fact, Pharmacode should be turned off when you are not scanning Pharmacode. The reason is that Pharmacode is not a well-designed symbology because it does not have a start character. It is therefore very easy for anything that is not a Pharmacode symbol to be decoded as a Pharmacode symbol anyway. This means that when you are scanning a UPC symbol it is possible for one or more scans to be decoded as Pharmacode instead of as UPC. (This is particularly true if your UPC codes are not well-printed and some scans do not decode as UPC.)

What is linear auto detect and why would I or wouldn’t I use it?

Linear codes are verified by 10 equally spaced scans. The distance from the first to the last scan is evenly divided. If you do not have linear auto detect turned on, the first scan will be at the top of the box, and the last scan will be at the bottom of the box. The box itself therefore, defines the “inspection zone”. Therefore, you should have the box drawn with the top and bottom inside the barcode.

If you do have linear auto-detect enabled, then you can set the box inside the code or outside the code. Making the box larger than the code makes it easier to position the label with the barcode inside the box and that is why you would choose to use linear auto detect. In this mode, the software will first try to decode on every row of pixels starting at the top of the box and continuing all the way to the bottom of the box. The first scan that successfully decodes will be used as the top of the bar and the last scan that decodes will be chosen as the bottom of the barcode. The inspection zone is then created automatically 10% down from the top and 10% up from the bottom. However, it is possible that a badly printed code can have un-decodable regions at the top and/or bottom and in this case the inspection zone may be incorrectly chosen by linear auto detect. That is one reason why you might not choose to use linear auto detect.

The size of the inspection zone is noted on the report, so you can check whether it corresponds (loosely) to the size of the code.

What is the difference between the GS1 software setting Auto and Always?

When the “Auto” setting is selected the software will grade codes according to GS1 standards whenever it detects an F1 character at the beginning of the code.

When the “Always” setting is selected the software will grade codes according to GS1 standards every time.

The 5-scan requirement is obsolete and that documentation is out-of-date. However, the verifier has the capability to average 5 results (because it was used previously before the requirement was removed from the ISO/IEC 15415 standard).

The new version of ISO/IEC 15415 explains why this requirement was deleted. Basically, it added very little value and was extremely difficult to perform. You can try it if you wish by turning on Avb. Angles in the 2D settings window as shown here. I think that if you do so, you will quickly agree that is very difficult to comply with. Since it is not a requirement of the standard you have no reason to actually turn on this setting.

What USB port settings should I be aware of for the TruCheck software?

Some computers are set up to disable the USB port hardware after a certain amount of time of inactivity. This can be prevented by:

1. Disable ‘USB Selective Suspend’ from advanced power options.
2. Change ‘Processor Power management -> Minimum Processor State’ from 5% to 100% from advanced power options.

What access settings do I need to allow domain users and users other than Admin use the TruCheck PC software?

1. Install the application as Administrator and not as the User with temporary administrative privileges.
2. Give read/write permissions to the ‘C:\ProgramData\Webscan Inc’ (Win 7 and 10) and C:\Documents and Settings\All Users\Application Data\Webscan Inc\ (Windows XP) folder to all users or domain users. (Note: ‘domain users’ must be entered explicitly).

I am not seeing live images when I am in live mode, I only see an image when I press verify what is wrong?

To find the driver of your Intel HD 4600, go into Device Manger from the control panel. Under Display Adapters, double-click on the Intel HD 4600. If the driver version is 9.XXXX then you must update the driver.

Notice : the video and audio driver is in one package. Your audio driver may be up to date, but your video may not.

To upgrade the video drivers to make sure TruCheck software runs correctly, please go to the following URL and download the Driver Update Utility.

http://www.intel.com/content/www/us/en/support/detect.html

Please install the utility, and then walk through the software update.

If it gives you a warning that the drivers are older, please go ahead and install the new version. (It recognizes the audio driver is up-to-date)

After installation, reboot the machine.

The driver version should now be 10.xxx.

Barcode Symbology Related Questions

How is Decodability calculated for UPC/EAN?

For each E distance, which is the pair divided by the module size, take the difference from the ½ module threshold between integers and divide by .5. So if two elements add up to 3.1 modules, that is .4 modules away from the 0 point (and .1 away from perfect) then its decodability is 4/5 =80%. There are two of these bar/space element pairs for each UPC character and the decodability is the lowest from the two (for that character).

For the ambiguous characters (1, 7, 2, 8), there is an additional check, which if lower, would be the decodability for that character. Essentially, it is the percentage distance from the threshold used to decide whether the character is the 1, 7, 2, or 8. This decision is based on the sum of the two bars in the character and how many modules they correspond to. It is not immune to bar width growth the way the regular bar/space pairs are.

What is Direct Part Marking (DPM)? How do I verify these types of codes?

Webscan is one of the only companies to offer a DPM verification solution. Direct Part Marking or DPM is the process of permanently marking an item with a barcode directly onto the surface. The preferred DPM symbologies are Data Matrix and QR Codes. There are over 15 different marking methods used to produce a permanent mark on parts. Webscan has two verifiers specifically designed to read even the most difficult of markings. For more information on DPM visit our symbologies page on Direct Part Marking.

If I print a Code 128 symbol and an I2of5 symbol, each with 40% bar width growth; one gets a C grade and one gets an F. Why?

First of all, this is a great opportunity to teach about decodability and the advantages of binary symbology (such as ITF or Code 39) versus Modular symbology such as Code 128, in cases where printing tolerances are large (as a percentage of the x-dimension). Because the wide:narrow ratio is more than 2:1 in the binary symbology, and essentially 2:1 for a modular symbology, the decodability is the bar width error divided by ½ dimension for the modular symbology, but it can be as much as the bar width error divided by the whole x-dimension (if the ratio is 3:1).

It is normal for ITF to get a higher decodability than Code 128, even if the x-dimension and BWG are equal. This is due to the design of the character set and the decode algorithm.

Why would a code pass ANSI verification but fail traditional verification?

Before there were any ANSI barcode grades, the original specification on barcode symbologies would place an allowable tolerance on the width for bars and spaces, such as plus or minus 20% of the nominal width. These tolerances were useful for printers and essential for pre-press. However, while the dimensions of bars and spaces is critical to reading a barcode, it is also critical that the optical properties of the barcode enables a scanner to find each bar and space so the widths can be measured. This was not adequately addressed by the traditional parameters. Moreover, while the traditional tolerances have a sharp point of failure at the edge of the tolerance, scanners do not have a sharp cutoff at this point. That is why ANSI grades progress through A to F levels. The reason a code can fail by traditional tolerances is that a bar or space width may be outside of the allowable tolerance, and that may result in a C grade in the ANSI system.

How can the overall ANSI grade be a “C” when none of the elements were lower than a “B”?
There are many ways this could happen. For example, the overall grade (the average grade for all of the 10 scans), could be a 2.1 (“C”). The grade for each of the 10 scans is the lowest value of any parameter.

If 8 out of the 10 scans decoded, alone it looks like an 8 for that parameter, but the score will include two “F” scans.

The 2.1 scan average comes from the 8 scans that decoded.

To see the details for each of the 10 scans, print a report with the settings Print Grid set to 1.

Why is CU (contrast uniformity) greater than 0 when I see some 0 values in the modulation table?
It is an anomaly in the spec. The module reported for CU is an ERROR (in such a case, you will also see that UEC is less than 100%). The CU value is taken without regard to the correct color of the module. This is an unfortunate situation, but that is the way it is in ISO 15415. On the value table, we report modules that are errors as 0 when they should be negative values. Basically, a summary is this: If UEC is less than 100%, CU is effectively 0% (although a different value will be shown for CU). If UEC us 100% then CU is correct as shown. Note that this should never occur on the CU test symbol on the GS1 Data Matrix Conformance test card.

What is GTIN-14?

GTIN is an abbreviation for Global Trade Item Number, which includes EAN-8, UPC-12 (UPC), EAN/UCC-14 and EAN/UCC-13 numbers. If your product has one of these barcodes, it will meet the GTIN-14 requirement.

General Barcode Questions

How do linear barcodes work?

Each character in a barcode is made up of wide and narrow bars. When the code is scanned, the reader illuminates the symbol. The white spaces reflect light back while the black bars absorb the light. An infrared sensor measures the relative width of the bars and spaces of the reflected light. The system translates this pattern to characters. Information is then sent to a computer or point of sale system where the characters are matched to a record in the system. Camera-based systems can also be used to read a barcode.

Who invented the barcode? What was the first product with a barcode?

Bernard Silver began preliminary barcode development in 1948 to help a supermarket chain read product information at the checkout stands. However, it wasn’t until the mid-1970s that the technology became developed into retail applications. U.S. Supermarket Ad Hoc Committee on a Uniform Grocery Product Code was formed during this time period. Four years later the first UPC was scanned at Marsh’s Supermarket in Troy, Ohio. The product was Wrigley’s Juicy Fruit gum, priced at $0.67.

Rarely Asked Questions

If you have a rarely asked question that is not listed below, email an engineer here at Webscan.

What is the effect of putting my film on a black, gray, or white background?

The translucency of white ink on clear film results in the background having a large influence on the measurement of contrast (and to some extent modulation).

A dark background, such as black or clear glass with a large enough distance between the glass and anything reflective will eliminate any reflection from the background. This would result in a measurement that was only dependent on the white ink.

Some people use a background that is intended to simulate, or match, the color of the item directly behind the film, when the final product is wrapped in the film. For example, using white to simulate white paper towels would be a reasonable thing to do.

Using a neutral gray color may be intended to fill in for an unknown color. On the other hand, using a black background (or equivalently glass with a gap behind it) is the best and safest testing technique for clear film using white ink as a background for the barcode.

Most barcode symbologies specify which elements should be light and which should be dark. For example, a UPC code begins with a light quiet zone followed by a guard bar pattern which begins with a bar. Since most barcodes are printed on light colored backgrounds they usually begin and end with a dark bar.

Scanners will generally not read a barcode if it is printed in inverse colors. Of course, the inverse colors are sometimes encountered in pre-press on negative films and our verifiers can be set to recognize a barcode that is printed in reverse colors. However, such a barcode, if having reverse colors in its final form, would be incorrect and not readable by most scanners.

When printing on a dark background, it is necessary and correct to print the light elements (the spaces) with a light colored ink. Then, the dark background serves as the bars. This would not be a reverse color barcode; only the process of producing it is opposite of the typical process.

If your customer has a special reason to print the barcode in reverse, they should understand that such a barcode is not in conformance with industry standards and will not be read by most scanners. Perhaps that is their goal – maybe they have a special scanner that is programmed to recognize these barcodes for a special application.

In such a case, you can set the Webscan TruCheck into a mode to check a barcode in an “Inverse Image” mode in which it expects the bars to be light and the spaces to be dark.

Why are my barcode grades varying even though the measured parameter values seem to be essentially the same every time?

You are noticing some variability in the overall resulting grade average and are noticing the range of values obtained for the individual parameters. The range for the individual parameters is very tight, and these results are considered very consistent. Note that the tolerances allowed with the ISO specifications are +-8 on DECODABILITY, SYMBOL CONTRAST, and DEFECT and as you can see, our measurements are tighter than this range of 16 levels.

The fact that relatively small variations in the measured values of the parameters can have a profound impact on the overall grade is a direct consequence of the way the overall grade is computed according to the spec. On each scan the parameters are assigned a grade level based on measured value. For example, if Symbol Contrast is between 50 and 62 it will get a B grade (equivalent to the number 3). The important thing to notice is that the values of several of your parameters can cross over the boundaries between grade levels. For example, the boundary between C and D for DEC (decodability) is at 37. So any time decodability is measured at 38 it will be a C but anytime it is measured at 36 it will be a D. Even a very small change in the actual value can result in a severe change in the assigned grade.

The actual grade result is thereby dependent upon the number of scans that fall on either side of the boundary which is somewhat random. Concentrate instead on the consistency of the parameter values, and note when they are close to a grade boundary.

In order to consistently produce symbols, that obtain passing (typically C) grades it is important to keep the print quality sufficient for all of the parameters to be above the minimum value for a C grade, taking into account the variability in both the printing process and the measurement process.

Since the measurement process variation, therefore affects your required print quality, it is important to have the most accurate and repeatable measurement device possible. That is why our TruCheck units offer the most accurate and repeatable measurements available in the industry.

Can I print my barcode in colored ink or on colored paper?

Using colorful paper or ink will reduce the contrast between bars and spaces, therefore reducing the barcode verification parameter Symbol Contrast (SC). Even printing black bars on a colored background could reduce the contrast ratio enough to hinder readability.

It is highly discouraged to use anything other than black bars on a white background because it will substantially reduce the ability for a scanner to read and decode symbols. Red should be especially avoided because many barcode readers use red light. If the bars are in the red color family, light will reflect off of both the red bars and the white spaces.

Before printing a colored code or on colored paper, remember that many retailers levy fines for unreadable barcodes.

What is the MR parameter in AIM DPM and what causes it to get a failing grade?

MR is slightly complicated to explain.

As you may notice, in AIM DPM mode, the image is adjusted so that when you have a low contrast symbol, it looks brighter than it really is. This is a fundamental part of AIM DPM system that is very different than ISO 15415. MR is a measurement of the brightness of the white elements (like Rmax). You will see that it can be very low on a low contrast symbol. Only if it gets very, very low (< 5) will it grade F instead of A. So, really MR is a limit on how much a low contrast symbol will be adjusted by AIM DPM process.

If you are failing MR, even after the system is calibrated, that means that the light elements of the symbol are very, very dark. (Of course, the dark elements are darker still, but that is expected). It means that if you were using 15415, your Rmax would be less than 5%, which is very low indeed.

What directory needs to have “full access” permissions for the users logged into Windows?
Program
‘C:\Documents and Settings\All Users\Application Data\Webscan Inc\’ on Windows XP
and
C:\ProgramData\Webscan Inc on Windows 7 or Windows 10.
(Note: this directory is HIDDEN on many computers — but it is there. Do not mistake this for the Program Files directory which is different.

How can I enable “domain users” to use the Webscan software?

Open Windows Explorer and browse to the ‘C:\ProgramData’ folder (Vista/7/10) or the ‘C:\Documents and Settings\All Users\Application Data’ folder (Windows XP).
Right-click on the ‘Webscan Inc’ folder and click on properties.
Click on the ‘Security’ tab and click on ‘Edit’.
Add either the group ‘Domain Users’ or the users that will be using the TruCheck Application.
Provide read/write permissions for the newly added group or users.
Important: Find the program in c:\Program Files(x86)\Websan Inc\TruCheck\trucheck.exe and make a new shortcut (send to desktop). Use this shortcut to run the program.