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Inertia dynamometers are commonly used to determine the friction coefficient of brake assemblies. Dynamometers are a well-established platform, allow testing under controlled conditions, exhibit a good correlation to many situations encountered in real driving, and are comparatively economical and less time-consuming than full vehicle test. On the other side of the spectrum is the use of scaled tribometer. These test systems make possible a test without the entire brake corner. This separation allows the investigation of the frictional-contact only (frictional boundary layer) speedily and independently of a given brake system or vehicle configuration. As the two test systems (inertia dynamometers and tribometers) may have different users with possibly different tasks, the question remains regarding how comparable the two systems are. These issues provide incentives to better define the fields of investigations, correlation, and applicability for the two systems.

For brake performance measurements, many standardized test procedures and machines were developed. A characteristic problem of these highly complex machines is the occurrence of measurement uncertainties, which usually are not predictable and rather difficult to explain. One part of explanations is driven by the huge but not yet complete list of influencing factors for the high load friction processes. Another part of explanations is given by f.i. manufacturing tolerances, load histories of machines and specimens and so on. A systematic investigation of these influences is very time-consuming and could be difficult to realize on professional test-machines [1]. On the other hand, simple laboratory tribometers are rather good for sensitivity investigations in principle but the friction systems are too far from the real system.

Dynamic aspects in the understanding of friction are increasingly coming into focus. Therefore, test arrangements are required, which allow dynamic measurements as well, especially with defined and reproducible sliding speeds. In addition, investigations of vehicle brakes require high power. A simple, reliable measurement device, based on the pin-on-disc principle, that meets these requirements was developed and will be presented here. This high load tribometer is based on a specially altered lathe. One key benefit of a lathe as a basic unit is the fact that the main mechanical part is standardized industrial equipment. Additional components and measuring devices can be integrated with little effort and great flexibility. The built-in 15kW AC motor and the embedded gearbox permit speeds and torques to the service areas of vehicle brakes, also of heavy duty vehicles and sports cars.