| 摘要 |
PURPOSE:To arrange so that a correct spectrum amplitude value may be obtained and real-time processing be made at site by analyzing a spectrum under FFT method and carrying out an evolution of the sum of square on a forward or a backward amplitude value centering around an elected amplitude value. CONSTITUTION:An output from an oscillation detection device 1 installed on a rotary machine passes through a filter 2 which removes a frequency component not necessary for the diagnosis of an abnormality and then is converted to an alternate or a direct current or vice versa 3. After this process, arithmetic operation is carried out on a spectrum distribution by means of a FFT-system spectrum analyzer 5 and a spectrum amplitude value is given to an amplitude magnitude distinguishing unit 5 and a sum of square evolution operator 6. The distinguishing unit 5 selects a meaningful amplitude value from among amplitude values which are output every frequency which is an integer time as much as a decomposition frequency set by an analyzer 4. While the operator 6 carries out a required sum of square evolution operation using as a base for judgement a large amplitude value selected by the distinguishing unit 5. As a result, it is possible to obtain an oscillation spectrum of the rotary machine in the form of a linear spectrum. |
