Barcode Verifier = Bar Code Quality Control
Businesses that must apply bar code shipping labels to meet customer requirements face expensive consequences if the labels are unreadable. Common consequences include refused shipments, charge backs, and eventually, disqualification as a supplier.
Fortunately, nearly all print-quality problems are preventable by consistently monitoring printer performance and implementing simple quality assurance steps. Common problems consist of:
- Bars are too light (underburn)
- Bars are too thick (overburn)
- Unwanted diagonal lines
- Spots are voids in the image
- Unable to sustain wide narrow ratio
- Poor edge definition
A simple quality assurance program can prevent some of these issues. Consistently monitor the label output and check for visible signs of problems. Look for uneven images, voids, spots, light printing, or overburn of bars in to space areas. Print head maintenance should be at the top of a quality assurance program. When you take care of the print head, quality printing typically follows.
Media can also be a factor in the overall quality of outputted labels. Poor quality media label stock will result in poor quality printed labels. Other factors that may cause printing problems are the printers themselves. Thermal printers may have ribbon wrinkles, burned out print head elements, improper heat and speed settings or a mis-marriage of the ribbon and face stock.
Printers today do produce high quality print and any printer type, if properly maintained, will generally print good bar codes. However, knowing that the printer is likely to print a good code means that inspection becomes less appealing. This means that bar codes go unchecked. Enter the need for verification. Bar code verification is the most certain way to assure that you are printing good codes.
A barcode verifier is not the same as a scanner. Using a scanner to read a bar code only assures that the scanned bar code has some region on it that is readable by that scanner. Therefore, the better the scanner, the less bar code quality assurance is maintained. A verifier, on the other hand, is a precision instrument made to predict how well the bar code actually is in reference to the specifications for its particular symbology. It should decode, measure and check formatting of even the most inferior symbol and indicate area(s) that are deficient so that corrective action may take place. Barcode Verification involves the testing of a bar code symbol’s print quality to determine how well that symbol will work when it is scanned or read.
There are two methods of bar code verification, traditional and ANSI. Traditional verification analyzes how well the code was printed. It looks at parameters such as print contrast, absolute element widths and average bar deviation. ANSI verification predicts how well a scanner incorporating a particular wavelength of light and a particular aperture size will read a symbol.
ANSI looks at eight criteria: edge determination, minimum reflectance, minimum edge contrast, symbol contrast, modulation, defects, decodability and decode. It does this by taking a scan reflectance profile of the code and analyzing that profile.
Verification should be done to ensure that the bridge between printing and scanning is accurate, to minimize faulty scanning and to ensure that inferior codes do not enter the system. Inferior codes cost time, productivity and money. If a code does not read at all, there is a return to the slow, error-prone manual data entry, and this causes bottlenecks or may stop enterprise-critical applications. If the code reads after several attempts, there is a waste of time and a chance of repetitive movement injuries. And if a code reads with errors, then there is a contamination of your database.
Bottom Line: TPI can improve your bar code quality control making you a better supplier to your customers.