Patent ID: 6876715

Claim:
A measurement system of torsion vibration for Reactor Internal Pump, including: a reactor internal pump that has a motor contained in a cylindrical motor casing and fixed by hanging down to the lower part of a reactor pressure vessel; a vibration detector fitted on the outer circumference of the cylindrical motor casing that detects vibration in radial direction; a sound detector fitted on the cylindrical motor casing that detects the vibration sound in the circumferential direction; a vibration calculating unit that receives the vibration waveform signal detected by said vibration detector, and the sound waveform signal detected by said sound detector, said vibration calculating unit calculating the difference in amplitude of said vibration signal and said sound signal thereby obtaining an axial torsional vibration signal of said motor; a frequency analyzing unit that obtains the spectrum of an axial torsional vibration obtained by the vibration calculating unit; and a display unit that displays the axial torsional vibration waveform obtained by the vibration calculating unit, and the axial torsional vibration spectrum obtained by the frequency analyzing unit.