I've heard that RFID doesn't work around metal and water. Does that mean I can't use it to track cans or liquid products?
Radio waves bounce off metal and are absorbed by water at ultrahigh frequencies. That makes tracking metal products, or those with high water content, difficult. However, good system design and engineering is beginning to overcome this shortcoming. Low- and high-frequency tags work better on products with water and metal. In fact, there are applications in which low-frequency RFID tags are embedded in metal auto parts to track them. Moreover, the introduction of foam-attached tags (FAT tags) from such companies as ADASA and SAVR Communications has helped reduce the impact of metal on RFID systems (see New RFID Products for Coping with Metal), while QinetiQ and Crown Holdings have worked to develop soft-drink cans and other metal containers with built-in EPCglobal Gen 2 UHF RFID tags designed to circumvent RF interference (see QinetiQ and Crown Develop Item Containers With Antenna-less RFID Tags). There are also ways to tag products with metal or water content to ensure reliabile read rates (members, see How to Tag Problem Products.)
