Executive summary
The Scottish Government have commissioned York EMC Services (2007) Ltd to evaluate the effect that acoustic and mechanical interference has on electronic identification ( EID) reader performance.
Desk based research was performed in order to identify any existing work that has been performed in this area and to gain technical information on the methods of operation of EID tag reading systems. This research showed that work performed in this area is extremely limited in both academic research and detailed studies.
Various EID reader manufacturers and distributors were approached in order to participate in this study in order to provide readers for testing and characterisation. EID readers were extremely difficult to be procured and with much effort, a total of 4 units were obtained for this study.
Site surveys for the characterisation of mechanical and acoustic interferences in auctions marts and abattoirs were performed in order to derive suitable test levels for laboratory testing. A total number of four sites were surveyed. The results show that the mechanical environment in these locations consists of random vibration of moderate level with short duration, but frequent bursts of high acceleration shocks. The acoustic environment consists of short duration, high intensity sounds that have considerable frequency content, extending to the ultrasonic range.
Laboratory testing for the acoustic study shows that loud sounds do affect tag readers such that their performance is degraded or completely inhibited. The study also shows that it is possible to design EID systems that are immune to acoustic interference as measured in auctions marts and abattoirs.
Laboratory testing for the vibration study shows that the all tested samples were affected by the vibration and shocks during the testing, with degradation varying substantially between samples.
All EID readers tested recovered fully and automatically on removal of both acoustic and vibration interference.
Laboratory testing for the study of the performance of the EID readers when used in non-metallic and metallic environment shows that the magnetic field amplitude can be reduced from 30% to 80% depending on the reader and demonstrates that metallic structures such as tubular fencing or kiosks (such as that used in the study) do greatly impact on the reading distance of the EID readers. The study demonstrates both experimentally and theoretically that the presence of metal has little effect on the quality factor of the EID system. It is also shown that EID readers have a limitation on the maximum read of individual tags at any pass, to a maximum of 6 in the EID readers tested.
Finally, the results obtained during the research could not be developed into a Code of Practice due to the build quality standard of the commercially available equipment that was under investigation for the use of EID systems in markets and abattoirs. Further research will be required to validate engineering concepts in order to propose suitable mitigation measures.