Radio Frequency Identification of product is the latest and most promising labeling system technology for inventory control or product tracking. It has current applications in the HF range but the future is in the UHF frequency range. HF, or high frequency, operates at 13.56 MHz, to ISO standard 15693. The standard assures that all labels and equipment match and work together.

The tag is a silicon chip attached to an antenna. The information is entered on the silicon chip. When the tag moves through a magnetic field, the antenna which is a long conductor generates a voltage which permits the chip to radiate its information. An antenna located near the container picks up the signal and passes it on to a receiver.

The advantage of the RFID tag over a bar code is that it does not have to be in the line of sight of a detector. The tag can be hidden and protected from dirt. Also, the process permits the simultaneous transmission of many tags. This way more information can be carried by one container or the tags of many containers can be read simultaneously.

A common method is to have the tag embedded in a label and applied with a label applicator. Some of these units can also encode the tag.

HF tags are made by Texas Instruments: TI-Tagit, and by Philips: I Code. They can be purchased through a number of label and printer manufacturers. Two types of tags are available. Class 0 read only and Class 0+ encode and read.

The limitation of the 13.56 MHz system is that the reading antenna has to be close to the tag. Depending on the size of the tag antenna, the reading antenna has to be within 5 to 24 inches. The receiving distance may go up to 4 feet with multiple tag antennas and a high performance receiving systems. Orientation of the tag to the reading antenna and the magnetic field has an effect on the clarity of the signal received.

The UHF systems in the US operate at 915 MHz. Agreement on a world wide frequency standard is still in progress. The advantage of the higher frequencies is that the antenna can be much smaller and the reading distance greater than with HF. The disadvantage is that the UHF signal, like with cell phones, can be affected by surrounding structures.

With both HF and UHF systems, the material of the container, as well as the contents, can have an effect on the system performance. Therefore, this technology is still in the growing stage.

The products listed here are 13.56 MHz and 915 MHz systems. Some of the models are HF capable now, but can be upgraded to UHF. The labels are all pressure sensitive. The label applicator manufacturers use printers made by the following companies: Datamax Corp., Sato America, Zebra Corp, Paxar, Printronix, Avery-Dennison. These companies also make bench top units and RFID starter kits.

The whole system, information software, encoding, stationary antenna, reader and data display requires that all components are compatible. For new users, it is recommended that they look at the processes recommended by the printer makers or one of the RFID systems makers listed.