The base unit HM 290 is required to supply different turbines. Additionally, the base unit enables basic experiments on a centrifugal pump. 

  The closed water circuit of HM 290 features a water tank and a centrifugal pump with variable speed via frequency converter. The turbine to be investigated (HM 288, HM 289, HM 291) is placed on the tank cover and is connected to the base unit via hose. The flow rate respectively the pressure applied to the turbine is adjusted by pump speed. The height of fall and the pressure upstream of the turbine can be kept constant by a pressure control. A damping plate inside the tank ensures a low air entry into circulating water. Basic pump experiments can be performed using the included throttle valve. The throttle valve is placed upon the tank cover instead of the turbine.

  The base unit is fitted with sensors for pressure and flow rate. The microprocessor-based measuring technique is well protected in the housing. All the advantages of software-supported experiments and evaluation are offered by the GUNT software and the microprocessor. The connection to a PC is made by USB.

  Following turbines are available: a reaction turbine (HM 288), a Pelton turbine (HM 289) and an action turbine (HM 291).

  The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

- basic experiments on a centrifugal pump

together with the turbines HM 288, 289 or 291

- determination of typical turbine curves
- performance curves at varying turbine speeds
- determination of efficiencies