## 6 Conclusions  
The implementation of the so-called \"sliding-gate\" dynamic method to measure in a faster way (up to ten times) the efficiency characteristics on hydraulic turbomachinery has been presented. The alternative testing measurement method has been successfully applied on two different cases dedicated to recover the energy dissipated by release valves of water supply networks: a 2.65 kW double-regulated laboratory prototype of an in-line axial microturbine with two independent variable speed counter-rotating runners and a 11 kW multi-stage centrifugal PAT with variable speed.  
The measurements have been carried out on the universal test rig of the HES-SO Valais//Wallis, Switzerland, dedicated to assess hydraulic performances of small-power turbomachines following the IEC standard recommendations. The applied procedure consisted, in a first step, on measuring the 3D hill-chart of a given testing model (turbine or pump) by the classical static point-by-point method. Then, a second digitizer has been installed to acquire synchronized dynamic signals of the sensors in parallel with the existing acquisition/control systems of the test rig and of the testing model. The dynamic measurements of efficiency have been performed at different constant speeds of the test rig recirculating pumps while increasing and/or decreasing the speed of the testing model runner(s) from zero to maximum, and vice versa, slowly enough in order to maintain a steady-state operation. Finally, the resulting 3D efficiency hill-charts of the two tested machines obtained by the dynamic have been compared and validated with the results obtained by the classical static point-by-point measurement method. Moreover, the S-shaped 4-quadrants characteristics of the PAT have been also successfully measured using the dynamic method.  
In conclusion, this approach is particularly gainful for small-hydro due to the reduced time required to perform the hydraulic efficiency tests. The same method could be interesting to rapidly identify the regions dominated by hydrodynamic instabilities within the operating range of a turbomachine.  
Wrote the paper, V.H., A.I.B. and C.M.-A.; Conceived and designed the experiments, V.H. and A.I.B.; Performed the experiments and analysed the data, V.H., A.I.B. and S.L.  
This research was funded by [the Swiss National Science Foundation] that supported financially [PERSON] through the International Short Visit program [grant number: IZK0Z2_163500, 2015].  
The present work was also founded by the Swiss Competence Center for Energy Research--Supply of Electricity (SCCER-SoE), granted by the Swiss Commission for Technology and Innovation (CTI). The development of the microturbine was carried out in the framework of Hydro VS project, in partnership with the Laboratory for Hydraulic Machines from Ecole Polytechnique Federale de Lausanne, Switzerland, granted by the program The Ark Energy of the Ark--the foundation for innovation in Valais, Switzerland. Finally, the PAT performance measurements have been done in the framework of the Svaise project, financially supported by Cimark and by the program The Ark Energy of the Ark, Valais, Switzerland. ClaVal Switzerland is also thanked for all their support with the release valves supply.