What is a dynamometer? A dynamometer or “dyno” is an instrument designed for measuring power and force. This can be measured in engines and motors as well as other items. This device is able to calculate power by concurrently measuring torque and rotational speed. This allows you to determine the required amount of power that is needed to run a given machine. If you need to know the power requirement essential to drive an engine, you would attach a dynamometer. This would then force a load on the engine, which is then measured to determine the amount of power needed. Other then just mechanical dynamometers these instruments are also used in an array of other areas like emissions testing, medical needs, and rehabilitation. One of the first instruments to be made was the Graham-Desaguliers Dynamometer invented by George Graham, which was made to measure muscular force. Then Froude Ltd. began to manufacture the engine dyno, and the first commercial instruments were established in 1881 by Heenan & Froude.