Water turbines are turbomachines utilizing water power. The Pelton turbine is a type of impulse turbine; such turbines convert the pressure energy of water into kinetic energy entirely in the distributor. During the conversion, the water jet is accelerated in a nozzle and directed onto the blades of the Pelton wheel tangentially. The water jet is redirected by approximately 180° in the blades. The impulse of the water jet is transmitted to the Pelton wheel.

FM 100.21 is a model of a Pelton turbine demonstrating the function of an impulse turbine. The experimental unit consists of the Pelton wheel, a needle nozzle used as distributor, a band brake for loading the turbine and a housing with a transparent front panel. The transparent cover enables to observe the water flow, the Pelton wheel and the nozzle during operation. The nozzle cross-section and thus the flow rate are modified by adjusting the nozzle needle. The turbine torque is determined by force measurement on a band brake and is read on spring balances. For measuring the rotational speed, a non-contact speed sensor. A manometer shows the water pressure at the turbine inlet.

The experimental unit is positioned easily and securely on the work surface of the FM 100 base module. The water is supplied and the flow rate measured by FM 100. Alternatively, the experimental unit can be operated by the laboratory supply.