Understanding microchips

Understanding microchips

Understanding microchips

What is a microchip?

Although the whole transponder unit is often referred to as a microchip, or chip, the microchip itself is actually the tiny computer chip that contains the ID number assigned to the transponder. The microchip itself measures approximately 1mm sq. Each ID

number during the Trovan manufacturing process is encoded onto the microchip by a laser that etches a code onto the surface of the microchip prior to the transponder assembly. The microchip is attached to an integrated circuit that uses a coil of copper wire wound around an iron (ferrite) core. This functions as a tiny antenna to pick up the energy from the scanner, and to send the encoded ID number from the microchip back to the scanner. Between the copper coil and the microchip in some transponders is a capacitor that is used to ensure the antenna transmits its signal at a consistent rate and also aids to boost the signal. Due to the Trovan microchip's unique design, there is no requirement for a capacitor.

The ID-162 FDX-B ISO Standards compliant series features transponders with factory pre-programmed 15-digit ID codes. The first three numbers denote the manufacturer – Trovan are 956. There are then a series of noughts and then 6, 7 or 8 digits. FDX means Full DupleX - the microchip is able to receive and transmit a signal at the same time. The ISO standards also describe HDX transponders, which stand for Half DupleX, these microchips receive, store and send a signal on a constant cycle - they cannot send and receive a signal at the same time. HDX transponders are commonly used in cattle ear tags, and are not used for implanation in companion animals.

What is a transponder?

A transponder is simply the whole electronic device encapsulated in biocompatible glass. The size of the petDetect transponders are Regular 2.12mm x 11.5mm and Mini 1.4mm x 8mm, both fall under the category of a ‘micro-transponder’. They can be referred to by many names including microchips, chips, PIT tags, transponders and RFID devices.

How do microchips work?

Electronic identification is also referred to as “radio frequency identification”, or RFID. The use of this technology allows a microchip programmed with a unique identification number, around the size of a grain of rice, to be implanted in an animal. Microchips contain no internal power source - when implanted in the animal, the microchip remains totally passive until a signal is sent from the microchip scanner. Each scanner has a coil antennae which functions to send a signal to the microchip when the scanner is passed close to it. The radio waves sent by the scanner give the transponder enough power to transmit its 15-digit number back to the scanner. Once the scanner has picked up this signal from the microchip, decoded it and displayed the number, the microchip then remains dormant until a scanner is passed over it again. As the microchip is passive and is only powered when the scanner is passed over the area, it lasts for the lifetime of the animal. Microchips themselves are only programmed with the unique 15-digit number, they do not contain any pet or owner details. These details are stored alongside the microchip number on a microchip database, such as Petog. Once the animal is scanned and the microchip number obtained, an authorised person must then contact the database in order to obtain the owner/keeper details.

Are all microchips used worldwide ISO compliant?

Prior to the implementation of the ISO standard across the EU and most of the world, various microchip technologies were developed and produced. Most of these microchips are FDX-A format, programmed with numbers which are 10-digits long. These FDX-A microchips are now mostly found in older animals, lab animals or those in zoos. Owners of long lived exotic pets such as birds or tortoises may find that their pet has one of these microchips. The FDX-A technology is also still widely used in the USA, who have decided not to adopt the ISO standards. AVID also produce an encrypted microhip programmed with a 9-digit long number known as the AVID FriendChip, which requires a brand specific or universal scanner in order to be read. Because there are many imported animals and because FDX-A chips are still widely used in the USA we always recommend that vets, rescues, customs staff and other professionals use a universal scanner to ensure that they can read these microchips. Although many scanners are available which can read both FDX-B and FDX-A microchips, these scanners are generally only able to read the Destron/FECAVA FDX-A microchips, they cannot read the Trovan Unique or AVID FriendChip.