<div class="htmlview paragraph">The roller brake dynamometer (RBD) is used to measure and evaluate the braking efficiency of road vehicles in periodic technical inspections (PTI). The quality of roller brake dynamometers is very important, to ensure adequate reliability of the periodic technical inspection and to ensure the road safety of motor vehicles. It is known that dynamometer measurements involve a large number of uncertainties. The brake force measurement covers the force mechanism, sensors, data acquisition, measuring and calculation programmes, roller diameters, friction surface, and calibration of the roller brake dynamometer.</div> <div class="htmlview paragraph">At the level of the ECE-13 regulations, the quality requirements and calibration methods are not specified. The Motor Vehicle Administration in Finland is running a project to develop quality requirements and calibration methods for roller brake dynamometers. The aim is to improve the reliability and to reduce the standard deviation at inspection stations and brake workshops.</div>