Eddy Current brake dynamometer:

Dynomec's Eddy current brake dynamometer is also used for same purpose as inertia dynamometer but eddy current dyno is better for performance tuning, because you can make load for engine, inertia type is more for measuring output of an engine.Dynomec inertia dynamometer measures the speed of an object, spun by the wheels of a vehicle, to come up with horsepower and torque numbers.On the other hand the eddy current brake dynamometer measures the horsepower and torque of a vehicle by applying varied levels of resistance to the drive line.

Comparing dynamometers runs on different days requires careful consideration of and adjustment for weather conditions. Air density and temperature can have a dramatic effect on engine output.

Vehicle comparisons made on different dynamometers may be more accurate on inertia dynamometers since calibration is not required.