Rfid for Weapons Tracking and Asset tracking: What is RFID?
There are two primary types of RFID that are used in tagging, tracking and finding items. RFID stands for Radio-Frequency Identification. The acronym refers to small electronic devices (labels and tags) that consist of a small computer chip and an antenna. The RFID device serves the same purpose as a bar code or a magnetic strip on the back of a credit card or ATM card; it provides a unique identifier for that object. And, just as a bar code or magnetic strip must be scanned to get the information, the RFID device must be scanned to retrieve the identifying information.
RFID versus Bar Coding
A significant advantage of RFID devices over the others mentioned above is that the RFID device does not need to be positioned precisely relative to the scanner. We're all familiar with the difficulty that store checkout clerks sometimes have in making sure that a barcode can be read. With RFID, items/tags can be detected 'many at a time' and 'from a distance', whereas bar codes have to be scanned with 'line of sight' from very close proximity. Further, with RFID, items can be FOUND with radio waves, whereas bar codes are essentially useless for finding missing items!
UHF RFID Overview
UHF RFID technology (Ultra High Frequency) utilizes tags that are powered by radio waves received from portable or detection-zone RFID scanners. A common example of UHF tags are the transportation cards (that hold a $ value available for fares) used by city metro systems. UHF tags do not send a signal unless they are being scanned by a radio wave. In the United States the radio frequency used for item tagging and tracking is 915 MHz. In other countries, the frequency varies between 840 and 955 MHz. UHF tags typically have a detection distance of up to 20' using portable scanners, or up to 40' when using detection-zone antennas. UHF RFID labels generally have a cost of approximately $0.20, depending on the material onto which the label will be placed, and the quantity procured.
Active RFID Overview
Active RFID technology utilizes tags that have a battery within the tag enclosure, that can be used as a partial or complete source of power for the tag's circuitry and antenna. Some active tags contain replaceable batteries for years of use; others are sealed units. A common example of active tags are the tags used in vehicle for auto-detection when passing through toll booths. Active tags have a typical detection distance up to approximately 300', or greater distances depending on the type of antenna implemented for detecting the tags. Active tags typically have a cost of approximately $15.00 to $50.00, depending on quantity, and depending on special features like motion sensing, tamper detection, temperature sensing, etc. The most common Active RFID frequency is 433 MHz