Example Applications - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 367

A large proportion of containers supplied today are identified by barcodes. However, in
industrial use the popular barcode system is not reliable enough, and its short lifetime
means that maintenance is expensive.
Transponders also have a much higher storage capacity than conventional barcodes.
Therefore additional information can be attached to the containers such as owner
details, contents, volumes, maximum filling pressure and analysis data. The transpon-
der data can also be changed at will, and security mechanisms (authentication) can be
used to prevent unauthorised writing or reading of the stored data.
Inductively coupled transponders operating in the frequency range < 135 kHz are
used. The transponder coil is housed in a ferrite shell to shield it from the metal
surface (see also Section 4.1.12.3).
The manufacturing process for the transponders is subject to exacting standards: the
transponders are designed for an extended temperature range from − 40 ◦ Cto + 120 ◦ C;
their height is just 3mm. These transponders must also be resistant to damp, impact,
vibrations, dirt, radiation and acids (Buhrlen, 1995).
Because the transmission procedure for transponders used in container identifica-
tion has not been standardised, various systems are available. Because a device has
been developed that can process all the transponder types used, the user can choose
between the different transponder systems — or may even use a combination of dif-
ferent systems.
Mobile and stationary readers are available (Figures 13.38 and 13.39). Stationary
readers can be incorporated into a production system which automatically recognises
and rejects wrong containers. After filling, the current product data is automatically
stored on the transponder. When this system is used in combination with database
management, the number of containers used by a customer for a given gas consumption
can be drastically reduced, because excessive standing times or storage periods can be
easily recognised and corrected. In addition, all the stations that the container passes
through on its way to the customer and back can be automatically recorded by the use
of additional readers. So, for example, it is possible to trace customers who return the
Figure 13.38 Identification of gas bottles using a portable reader. The reader (scemtec SIH3) is
designed to function with transponders from different manufacturers (reproduced by permission
of Messer Griesheim)