| 摘要 |
PURPOSE:To discriminate an abnormal vibration with good accuracy by arithmetically processing a vibration waveform of the outside wall of the case of an electric apparatus with a filter, a sampling circuit, etc. CONSTITUTION:Vibration waveforms of the outside wall of the case of an electric apparatus detected with a detector 1 are amplified with an amplifier 2. The amplified vibration waveforms are passed through a filter 4, whereby the electromagnetic vibrations of low frequencies are removed, and the output thereof is inputted to an arithmetic unit 5, which samples the same by dividing this into the plural sampling periods of the same phase and the same length, operates the absolute value at each sampling period, adds and averages the absolute values through each sampling time and has the results thereof drawn by a recorder 3, whereby the presence of any abnormality in the electric apparatus is judged. |
