Barcodes

Barcodes can be produced quickly and simply, moreover, they can be read with relative low priced devices. However, they have a short reading distance and cannot read destroyed or dirty tags. Modern, more expensive bar code readers or the usage of point codes improve results in this case. By frequent using (e.g. to identify vehicles) the barcode can be applied onto PVC-, credit card sized tags. The barcode can be engraved into metal via laser technology, if heat resistance is necessary. The range of bar code reading devices reaches from ball pen-like pen readers for offices up to camera supported systems, which are able to read large bar codes up to 10m of distance.

RFID-Identification systems

Frequencies of the long-wave range are used for "radio frequency identification“devices with active and passive tags. Active tags send, when activated by the transmit/receive-device, stored data back on their own. For that, they need a battery as power supply inside. Passive tags reflect the carrier frequency including a code in modulated form, due to this, they have less data available. The allocation is carried out by software connected to the reading device. These tags are available in the form of cards, key rings, buttons or other forms and are relatively low priced. They have a low reading-range (10-40cm), show a rather high sensitivity against electromagnetic faults and, due to the fact that they work with a low frequency, the passing speed is also very low (4-7 km/h).

Microwaves-identification systems

This systems use microwaves in the range of 2,4GHz as carrier for information. A tag is activated by coming into the microwave coil and it reflects its stored data contents. Some tags have programmable data areas in addition to the fixed data contents. Microwaves-identification systems are newest technology and they are non-sensitive to interference of all cases, they catch large amounts of data and have reading distances up to 12m. Nowadays, tags that can be used for high environmental temperatures (like burn-in paint shops), high crossing speed up to 200 km/h (e.g. the identification of railways) or rough environmental conditions (Heavy Duty Tags) are available. The disadvantage of this technology is the limited durability of the tags and in the higher price, which is much more than that of a RFID-device.