At any one time, Mercedes Benz engineers are putting some 1,800 test vehicles through a rigorous set of trials. Among the many things that Mercedes engineers evaluate on these cars are different combinations of tires and wheels. In fact, some 20,000 tires and wheels are stored in a warehouse at the Mercedes test facility in Stuttgart, Germany.

Keeping track of all these tires and wheels isn’t easy. In the past, engineers coded the tires manually by burning in a number using a special thermal process and then coloring the digits white to make them easy to read. The wheels were engraved with a needle. Both procedures were time-consuming and error-prone. Staff had to visually read the number and enter each digit into the computer system for stock control and analysis.

As the warehouse grew, Mercedes engineers decided to implement an automatic data collection system. They had to find a code small enough to fit into tight spaces. Because tires and wheels are round, a traditional bar code could not be used. Instead, the Data Matrix code was selected, because it could encode an 18-character alphanumeric identification code on a label as small as a penny.

The next consideration was the label. It had to withstand harsh mechanical, chemical and thermal conditions. Mercedes chose a silver label and a special adhesive that would withstand the harsh conditions.

The labels are printed with the B-472 thermal transfer printer from Toshiba TEC Europe (Brussels, Belgium). With a stainless steel case and internal media supply, the printer can be used in harsh operating environments. It also features a near-edge floating printhead, which enables the machine to print at high speeds on a wide range of media. At a resolution of 203 dots per inch, the machine can print labels at a speed of 10 inches per second. The maximum print width is 104 millimeters. The maximum print length is 997.9 millimeters.

The labels are read by handheld scanner, which transfers the data by radio-frequency communication to the host computer.

For more information about Data Matrix codes and label printers, call 32-02-410-2100 or visit