| 摘要 |
PURPOSE:To arrange so that a correct spectrum width and its frequency may be detected on real time basis at a site where equipment is installed by making a frequency integer times as much as the resolution frequency of a spectrum analyzer agree with the number of vibrations of a rotary machine. CONSTITUTION:A vibration frequency spectrum is claculated by means of a vibration detection device 1, a band filter 2, and A/D converter 3 and a digital frequency spectrum distribution calculator 4, based on a vibration value input generated by a rotary machine. Next, the maximum value of a spectrum amplitude is compared with the amplitude of each front and back set of side band spectrum of said frequency. If their ratio is at a value higher than prearranged, a sampling interval is increased or decreased according to the comparison results of the both side band spectra. If the frequencies of the both side band spectra are below the prearranged ratio, an arithmetic operator 8 operates a resolution frequency and a digital printer 9 prints out the maximum frequency and amplitude of a frequency spectrum. Under this constitution, it is possible to convert the resolution frequency to a linear spectrum in frequency spectrum analysis. |
