A dynamometer is a type of test stand that measures force, torque, power, speed and other factors. A motoring dynamometer determines the torque and power required to operate a driven machine, along with other factors like friction and losses. An absorption dynamometer measures operating torque and speed, while acting as the load being driven by a prime mover. A universal dynamometer can serve both motoring and absorption functions.
An electric motor generator dynamometer is a specialized type of test stand on which the motor generator can operate as a motor that drives the unit being tested or as a generator that is driven by the unit being tested. These types of test stands also can be configured as universal dynamometers.