Do I Need a 1D or a 2D Barcode Verifier?
Sounds like a simple question but the answer isn’t always that straightforward. It depends on a lot of things. For example, what kind of a shop are you? If you are a commercial printer, you never know what’s going to come through the door or the email. Even if you’ve never printed a single Data Matrix or QR Code, the day will come when you will and you’d better be ready. But first let’s talk about what a 1D and 2D barcodes are.
- A 1D barcode is a single row of parallel lines and spaces—think UPC.
- A 2D barcode (which technically isn’t really a “barcode”) is a square or rectangular pattern of square (or sometimes round) dots or elements, arrayed in both the X and Y axes.
But there are variations. There are barcodes that are technically 1D but are multiple rows of parallel lines and spaces, also known as stacked linear barcodes, such as PDF417 (look on the back of your state issued driver’s license) or GS1 Databar coupon codes (see your Sunday newspaper ad section). Aren’t these really 2D? Well yes, they do occupy two axes but no, the data is not encoded in two axes, it is encoded in parallel rows, line a page of text.
OK, now that we have the basics, what can a 2D verifier do that a 1D verifier cannot? Another simple question with a not-s-simple answer. Most 2D verifiers can test and grade 1D barcodes (did you know that?). But (yes here it comes again) 2D verifiers are limited to the field of view that the digital camera/scanner covers, and most 1D barcodes are much longer than they are tall. Consequently a 2D verifier can only accommodate a limited range of 1D barcode sizes.
There is another consideration with 2D verifiers: X dimension or narrow bar (or element) width. In addition to having a limited field of view, digital camera scanners have a set minimum aperture size beneath which they cannot accurately resolve a finer bar width. Think of it this way: you either get a larger field of view or a very fine resolution. In most cases you cannot have both. So if you need to verify Data Matrix codes with elements as small as 8 mils, you cannot reasonably also verify big ITF14 barcodes on corrugated with the same verifier.
One additional consideration from my days as a sailor. We had a boat with a compass, a separate clinometer, a wind speed and direction indicator and a boat peed indicator all occupying a fair amount of space in the cockpit. During a rebuild we considered replacing all of it with a single instrument. Then a fellow sailor advised us against it because when one breaks—or in the case of a verifier, when it’s back at the factory for recalibration—you are without your entire instrument cluster. Separate instruments will cost you a little more but will keep you functioning at some level all the time.