How To Choose a Bar Code Scanner
The most common use of bar code scanners, and the one that most people are aware of, is the scanning of groceries at a grocery store. At the teller the bar code of each package is run past a barcode scanner that tells the system what the item is. The stock control system then feeds back item details and price information to the teller. The cost is automatically added to your bill.
When the stock control system tallies a purchase, no matter what is actually sold, the inventory records in the central database are simultaneously modified to record the fact that the item has been purchased. If your inventory information was correctly entered into the system when you set it up, inventory control occurs without the need for manual counting or recording of purchases.
In a small business setting implementing such a system starts with stock control software where information about inventory items is stored. Bar code scanners are used to input data into the stock control system. Each time an item passes in or out of inventory it is scanned and the appropriate change of status is recorded in the inventory database.
Such a system can even create unique bar codes for items that do not already have them. For new items a unique bar code is generated by the software, and then a bar code printer is used to print a bar code label that is then affixed to the item.
The three most prevalent kinds of bar code scanners available now are:
1. The Wand Scanner – The most basic type of bar code scanner is the “wand”. This is a pen-type scanner that needs to be kept in contact with the bar code when scanning it. The wand emits a light which is reflected off the bar code and then decoded by the system to identify the item.
The wand system works very well most of the time, and is is the cheapest kind of bar code scanner. As far as cost is concerned, one of these wands will cost 1/10th as much as a laser gun, and about 1/5th as much as a CCD scanner.
But wand scanners have their limitations. In order to get an accurate scan the wand must be held at a fairly precise angle relative to the bar code. It must also be slid across the bar code at a speed that is neither too fast nor too slow. And all wand bar code scanners have a resolution limit. If a bar code has a resolution that is significantly finer than the wand scanner, the scanner will not be able to read it correctly. For example, a 10 mil wand cannot read a 5 mil bar code. It is important to keep this in mind when purchasing a wand scanner.
2. The CCD Scanner – CCD (charged coupled device) technology is the next least expensive bar code scanning system. Like the wand scanner, CCD readers must be in direct contact with the bar code label in order to read it. But unlike the wand, there is no need to move the device across the label. The operator simply presses the reader against the label and pulls the trigger. The bar code is then photographed, digitized and decoded by the system.
Of all the different types of bar code scanners, CCD readers are considered the most straight-forward to use. They are manufactured in widths that start at about 2 and go up to 4 inches. A CCD reader is expensive compared to a wand (about four times the cost), but is a bargain compared to the laser scanner (about one third the cost).
A promising new technology similar to CCD is called FFO (Fixed Focus Optics). These scanners are non-contact readers, which means they can read bar codes from as much as 20″ away. They will also be able to read two-dimensional bar codes as they become more popular.
3. Laser Scanners – A beam of light is used by a laser scanner in order to scan the bar code label. Instead of moving the scanner you move the bar code across the scanner. The scanner does not have to actually touch the bar code label in order to read it. The scanner will automatically read the scan whenever a bar code is held in front of it.
This system is popular in many different settings. For example, since scanning is done rapidly, laser scanners can be embedded right within conveyor systems. As objects pass quickly by they are scanned and recorded. In retail stores the check out person simply moves objects over the scanner to activate the scanning action. This kind of system is fast enough to keep up with a clerk just taking objects from one side of the scanner and sliding them to the other side. Such a system is much faster and much more accurate than any of the popular alternatives currently available.
No matter what your ideal scanning system might be today, you need to make certain that you buy a stock control system that allows you to take advantage of future developments in bar code technology. This will allow you to keep your system updated without having to replace the entire system in the future.
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