The system for the investigation of fluid-flow machines is clearly laid out on a sturdy frame. The usage of corrosion resistant materials for the pipework keeps maintenance effort low. The fluid-flow machine is in a transparent housing so that the effects of the blades and flow can be clearly seen. Electronic differential pressure measurement on the different blade stages and the additional blades supplied with adjustable blade angle enable impressive experiments to be performed. A water tank enables the fluid-flow machine to be modified without the loss of water. The range of experiments is considerably extended by the fact that the fluid-flow machine can be operated both as a turbine and as a pump. In turbine operation the fluid-flow machine is driven with the aid of a powerful pump. The motor/generator attached to the fluid-flow machine is designed as an asynchronous machine with frequency converter. This enable braking energy to be returned to the mains on operation as a turbine. The measured values are measured using electronic sensors indicated in easy to read form on digital displays. A detailed two-part instruction manual is included. In Part 1, amongst other aspects, placing the system in operation and changes to the fluid-flow machine are described, whilst in Part 2 the experiments are discussed in detail.