• What can influence RFID read range?
• What is the correct frequency for my application?
• What are the differences between "multi-read" and "single-read" systems?

What can influence RFID read range?

The textile and laundry industry with its washing, ironing, folding and sterilization processes is a very good example of a noisy and "difficult" environment. Humidity absorbs magnetic fields, metal reflects and distorts radio signals, neon lights interfere with electromagnetic waves, electrostatic electricity gathered from the hanger or conveyor systems not only interferes with but also modifies signals, vibrations alter frequencies and strong power supplies for machines and computers add to the problems. These factors can influence the actual read range of a transponder in the field.

What is the correct frequency for my application?

Each frequency offers properties that suit some applications better than others. Additionally RFID manufacturers have developed optimized application-specific systems that offer enhanced performance. Datamars, for example, has equipped all its industrial antennas for laundry applications with a patented central noise canceling system (CNCS) that enhances tremendously the reading range within the typically "noisy" laundry environment. This system is coupled with a LED noise signal meter, fitted on the Datamars industrial reading unit, which continuously monitors the noise level and can be used to tune the antenna by shop floor personnel.

What are the differences between "multi-read" and "single-read" systems?

The major difference between these systems is direction of the data flow between the reader and the transponder. In the single-read transponder systems there is no transmission of data from the reader and the transponder, but only from the transponder to the reader. The transponder sends its ID code to the reader as soon as the magnetic field is strong enough to give it energy to perform. In the multi-read transponder system a dialogue exists between the reader and the transponder, which will give its ID code only if asked. This dialogue takes time and slows down the effective reading speed. It is possible to limit the dialogue to one demand and one answer (depending on the transponder) if there is only one transponder within the field of the antenna.

• What is understood by the term 'migration'?
• Is there any scientific data that describes the comparative behavior of transponders, from different manufacturers, when implanted in animal tissue?
• Is the injection of the transponder painful for the animal?

What is understood by the term 'migration'?

Migration means a physical movement of the transponder of more then 2 cm from its original implant site in the animal. It is important to note that the "extent" of migration is not always easy to define, as the notion is relative to the size of the animal i.e a migration distance of 5 cm in a large German Shepherd is not a problem, but the same distance in a tiny Yorkshire terrier is more significant. In other words one must always measure the migration in relation to the size of the animal.

Is there any scientific data that describes the comparative behavior of transponders, from different manufacturers, when implanted in animal tissue?

All implanted transponders, regardless of the manufacturer have a tendency to move within the animal's tissue to some extent or another. The J.A. Jansen clinical study (Biological and migrational characteristics of transponders implanted into beagle dogs - The Veterinary Record, September 18, 1999) clearly demonstrated that, when the site of implantation was near the head close to the base of the ear, there was no significant difference in migration characteristics between the different types of transponders i.e those with an anti-migration cap (consisting of polypropylene polymer) and those without. All transponders implanted in that site either did not migrate or migrated less than 2 cm. Such a distance cannot, by any means be considered as a significant migration.

Is the injection of the transponder painful for the animal?

No, it takes the veterinarian only a few seconds to implant the microchip under the skin of the animal and often the animal doesn't even show a reaction.