An Examination of the Variables Affecting RFID Tag Readability in a Conveyer Belt Environment

There is a growing list of companies implementing radio frequency identification (RFID) systems to help optimize their supply chain processes. These companies realize that a successful RFID system can potentially lead to lower supply chain inventory levels, re­ duced operating expenses, and greater visibility throughout the sup­ ply chain. However, since RFID technology is still relatively immature, a majority of the applications experience less than perfect read rates for tagged items moving through the supply chain. This paper reports the results for a variety of different arrangements of variables that may influence the readability of the RFID tags in a conveyer belt environ­ ment. The variables tested for this study were tag placement on the package, tag orientation, conveyer belt speed, tag type, package contents, and the reader antenna distance from the conveyer belt. The goal of this research was to determine how these variables influ­ enced the readability ofthe RFID tags. The results from this procedure determined that metal and water have a negative affect on the read ac­ curacy of the RFID tags. The read accuracy also decreased as con­ veyer belt speed increased, and as a function of the distance between the antenna and the conveyer belt. Multiple linear regression was used to create 'Hit Rate' equations that can be used to predict the hit rate for the three types of products tested under various speeds and distances.