## 3 Experiment  
Figure 4 shows the hydraulic installation for testing the piston-axial pump (Table 2), which consists of the following: 1. tested pump; 2. vibration-measuring transducer; 3. reducer; 4. incremental rotary encoder; 5. electric motor; 6. cylinder pressure transducer; 7. pressure transducer in pressure chamber; 8. manometer; 9. absolute pressure transducer; 10. faucet; 11. measuring turbine for flow; 12. valve for pressure limitation; 13. return filter; 14. power with vent; 15. thermometer in the tank; 16. refrigerator; 17. working fluid level indicator; 18. heater; 19. suction tap; 20. suction filter; 21. manovacumeter. Figure 4: Hydraulic installation for the tested pump experiment. 1. Tested pump; 2. vibration-measuring transducer; 3. reducer; 4. incremental rotary encoder; 5. electric motor; 6. cylinder pressure transducer; 7. pressure transducer in pressure chamber; 8. manometer; 9. absolute pressure transducer; 10. faucet; 11. measuring turbine for flow; 12. valve for pressure limitation; 13. return filter; 14. power with vent; 15. thermometer in the tank; 16. refrigerator; 17. working fluid level indicator; 18. heater; 19. suction tap; 20. suction filter; 21. manovacumeter. Figure 3: Visual representation of forces. Pressure transducers, based on measuring tapes type P3 MA, range 500 bar, accuracy class 0.1, and bandwidth 100 kHz (Figure 5), were used to measure the pressure in the cylinder and pressure chamber of the pump. The flow measurement was performed with a measuring turbine type RE2 25/180 L/min, accuracy class 0.4. An incremental encoder type ROD 426 E, with 1024 optical markers and a maximum number of revolutions of 12,000 min\({}^{-1}\), was used to measure the rotation angle of the pump's drive shaft. Using an accelerometer with a measurement range of 5 m/s\({}^{2}\), the vibration amplitudes of the housing were measured. The ultra-fast measurement and control system ADS 2000-CADEX (Figures 6 and 7) enables the continuous measurement and calculation of the characteristic parameters of the pump's working cycle in real time. \begin{table}
\begin{tabular}{c c} \hline Number of pistons & z = 8 \\ \hline Nominal pressure & P\({}_{\text{N}}\) = 200.0 bar \\ \hline Suction pressure & P\({}_{\text{s}}\) = 4.45 bar \\ \hline Volume of the pressure space & V\({}_{\text{S}}\) = 2.71 \(\times\) 10\({}^{-4}\) m\({}^{3}\) \\ \hline Radial clearance of the piston in the cylinder & r\({}_{\text{FC}}\) = 9.78 \(\times\) 10\({}^{-6}\) m \\ \hline Volume of the harmful space & V\({}_{\text{HS}}\) = 30.25 \(\times\) 10\({}^{-6}\) m\({}^{3}\) \\ \hline Angle of the beginning of the suction phase & A\({}_{\text{SP}}\) = 31.030\({}^{\circ}\) \\ \hline Stiffness of the pressure valve spring & S\({}_{\text{VS}}\) = 1108.0 N/m \\ \hline Mass of the pressure valve plate & m\({}_{\text{VP}}\) = 4.3310\({}^{-3}\) kg \\ \hline \end{tabular}
\end{table} 
Table 2: Technical data of the tested pump. Figure 5: Measuring transducers on the tested pump; 2. vibration transducer; 6. pressure transducer in the cylinder; 7. pressure transducer in the pressurized chamber. The processor takes data from the A/D converter in real time directly into the CPU-DRAM. At the same time, the processor controls the amplifier and multiplexer cards in real time. Software for measuring cyclic and non-cyclic rapidly changing processes with a graphic online display was developed for the system. The statistical processing of the measured data in the measurement process is performed with a graphic display. The maximum measurement speed is 3 MHz with 6...12 simultaneous A/D converters at 50,000,000 measured data in one ensemble. Up to 4 VME-CPU cards with Motorola 68020...68060, Intel Pentium, Digital Alpha, or Motorola Power PC processors can be integrated into the system. Figure 6: Structural diagram of the applied ultra-fast measuring system ADS 2000-CADEX. The VME-bus ADC system uses ADC cards, each containing two 12-bit A/D converters, each with a sampling rate of 350 kHz, operating simultaneously.