The working mechanism of hydraulic dynamometer is similar to centrifugal water pumps. In these dynamometers, one or two bladed rotating discs are installed on the central rotor. This rotor is placed inside a fixed shell as a stator and the space between them is filled with an intermediate fluid like water. Through the production friction between the rotor and the stator, the braking force is applied to the rotor and the amount of braking force is transferred to the stator based on the law of action and reaction, and the amount of braking torque is measured in the stator using an arm and force.
The amount of braking load is proportional to the amount of fluid entering the dynamometer, which is controlled using the inlet valve. The absorbed force increases the temperature of the water (cooling fluid). The maximum allowed water temperature at the exit from the dynamometer is 70 degrees Celsius.
The rotation speed of the rotor is measured using the induction sensor inside the dynamometer, and the amount of absorption power is calculated from the product of the torque and the speed.
