CARDIFF-A Calibration Method for Mechanical Dynamometers

A new method, CARDIFF, has been developed for calibrating chassis dynamometers. This method is based upon the determination of the frictional losses attributable to each inertia flywheel of the dynamometer system. Frictional losses for any inertia combination are found by the summation of individual flywheel contributions. The dynamometer load setting, which is critical for emissions and fuel economy testing, is simply obtained by subtracting these losses from the required actual horsepower.

This method increases testing efficiency by reducing the calibration time by approximately 75% as compared to the generic procedure defined in the Federal Register.