Many people are used to scanning bar codes with laser scanners at supermarket checkout counters to identify goods. At the same time, bar codes are used to identify parcels and letters in the postal system. AVID's electronic identification system provides essentially the same ability for animal identification, while the ID system using tags is not practical here.
There are two basic differences between electronic identification system and bar code identification system: how to read ID code and how to store it. Electronic identification systems use public low-power radio signals to read ID codes stored in microelectronic circuits instead of using lasers to read labels. Electronic identification systems based on these radio signals are also called radio frequency identification systems or RFID. Unlike light, these low-frequency radio waves can penetrate all solids except metal materials. Therefore, the application of electronic identification system can allow numbers to be permanently stored in animals without being lost, destroyed or worn and unreadable like external dog signs.
A miniature electronic device used to store electronic identity numbers is called a transponder. AVID's transponder comes in three sizes, and the smallest one is like a rice grain that has not been steamed. All transponders can be easily injected into animals, just like ordinary vaccines. This device remains in the animal for life, and when it is scanned by a compatible electronic identification reading system at any time, it provides the unique ID number of the animal.
Most AVID reading systems or scanners use the frequency of 125khz to transmit signals, which is much lower than the frequency used for AM medium wave broadcasting. The energy of radio signal emitted by scanner is less than 1 MW, which is much lower than that of children's dual-frequency radio. AVID's scanner has been approved by the FCC organization in the United States and similar organizations (PTT) in other countries, and can be used as low-power RF equipment without being restricted by local use licenses.
AVID's transponder (microchip) is a passive device, which means that the transponder has no battery and is inactive most of the time. The microelectronic circuit of the transponder is powered by low-power radio waves sent by compatible reading equipment. The transponder sends the ID number back to the scanner in the form of radio waves, and then the scanner decodes the number and displays it on a small screen similar to an electronic calculator. Because the transponder does not contain a battery, energy exhaustion will not occur.
The microchip is cylindrical, with a minimum size of 1 1mm and a diameter of 2.1mm. The internal structure has only three parts. The first part is the computer microchip (highly integrated circuit). The microchip contains the unique ID number assigned to the transponder, and all the electronic circuits needed to send the number to the scanner when it receives the radio signal from the scanner. The second part of the transponder is a coil made of copper wire wound on a metal core. The function of this part is as a small wireless antenna to receive the signal from the scanner and send the coded ID number of the microchip back to the scanner. The third part is the capacitor used for tuning.