| What is the best choice between bar code and RFID? | | | | Metal surfaces reflect RF while liquids absorb RF and |
| This, in many cases, is the million dollar question. There | | | | in both cases will affect the readability of the tag. |
| are a lot of people interested in RFID for various | | | | While there are tag designs to help minimize the |
| reasons and many early industry articles over-hyped | | | | effects of RFID on a metal surface that design may |
| RFID with the supposed nickel RFID tag. In addition, | | | | not be the best design for another surface, i.e. plastic. |
| opinions are often slanted towards companies’ | | | | Cost and longevity are also factors to consider when |
| primary operations. For example, bar code companies | | | | deciding on an ID technology. Whether you are dealing |
| will justify bar code as the best option while RFID | | | | with bar code or RFID installation is a major cost. |
| companies will justify the newer technology of RFID | | | | Therefore, although the actual cost of the ID itself is |
| as a superior solution. The emphasis needs to be on | | | | not significant incurring additional installations costs can |
| efficiently managing data, not on the actual system to | | | | dramatically affect the overall ROI for a project. |
| accomplish this. | | | | If either RFID or bar code technologies are acceptable |
| There are many methods of collecting and managing | | | | based upon environment, read range and surface |
| data: manual, magnetic stripe, OCR, bar code and, of | | | | conditions, determining ROI is the next logical step. |
| course, RFID. What is the most practical method of | | | | Remember to take into consideration the infrastructure |
| collecting data for your operation? Keep in mind that | | | | (hardware, middleware, software), ID investment and |
| the latest emerging technology is not always the best | | | | the cost of installing the ID. If after weighing the |
| choice. Perhaps direct parts marking or bar code | | | | information RFID is the technology of choice, why not |
| labeling is more practical and will provide the best | | | | also consider using bar code? Adding bar code to an |
| return on investment. Evaluate all practical data | | | | RFID tag is a minimal additional investment that could |
| collection methods and do not automatically | | | | reap many benefits. For example, not all locations may |
| predetermine a data collection method. | | | | be able to support the RFID infrastructure required. |
| Environmental conditions not only determine the ID | | | | In summary here are a few signals that bar code |
| method, but also factor in to the ID design. For | | | | should be used as your primary ID technology. |
| example, will the RFID or bar code label be exposed to | | | | 1. Small number of assets being tracked at once |
| heat, UV, abrasion, chemicals or solvents? What kind | | | | 2. Data collection done on a batch basis |
| of impact will they have on the performance? We | | | | 3. Severe environmental conditions (RFID may not be |
| know that in higher temperatures (>300°F) the | | | | practical – i.e. heat, shock, abrasion, severe chemical |
| leads break away from the RFID inlay destroying the | | | | exposure) |
| data. The amount of exposure to UV, chemicals, and | | | | 4. Near field to medium read range is acceptable |
| solvents usually determine the RFID label design. | | | | 5. Extreme metal content – isolator not acceptable |
| Another factor to consider is the expected read range | | | | 6. Noisy RF environment |
| for an ID product. Bar code tends to have a closer | | | | 7. Data collection speed not an issue |
| read range than RFID, although there are materials that | | | | By contrast, here are a few signals that RFID should |
| help extend the read range for bar codes, i.e. | | | | be used as your primary ID technology. |
| retroreflective material. In addition, bar codes need to | | | | 1. Reading multiple items in a short period of time (case |
| have a direct line of sight in order to be read where | | | | lot unit, containers, pallets, etc.) |
| RFID tags don’t. The read range for RFID tags is | | | | 2. Mild to moderate environments |
| highly dependent on the inlay used; however, in general | | | | 3. Little RF noise |
| terms passive tags are going to have a read range up | | | | 4. Long or extended read range required |
| to about 20 ft.; where active tags are going to extend | | | | 5. Read range is acceptable from metal mount |
| read range beyond that. | | | | surface |
| The items being tracked are also a key factor in | | | | Remember, RFID is not automatically the best choice |
| determining which technology to use. Is the item metal, | | | | when evaluating ID technology. Consider the |
| plastic, wood, etc.? Manual methods or bar code work | | | | environment to which the ID will be exposed, read |
| on nearly any surface condition without affecting | | | | range, and surface conditions to ensure you will |
| readability; however, RFID reacts to different surfaces. | | | | receive the maximum ROI for your specific application. |