Abstract: An apparatus of an embodiment includes a unit to calculate a parameter of a frequency component in a sound, calculate an average of amplitudes and an average of frequencies based on an amplitude spectrum of the sound, if the parameter is smaller than a third threshold, and perform at least either of comparison between the average of the amplitudes and a first threshold and comparison between the average of the frequencies and a second threshold; and a unit to, if a result of the comparison satisfies a condition, acquire values and frequencies of peaks included in an amplitude spectrum based on a portion of the sound, calculate ranks of the values of the peaks times for different portions of the sound, and determine a cause of an abnormal sound based on a total score obtained by summing scores set in accordance with the ranks.

Abstract: According to the embodiment, there is provided a blade vibration measuring apparatus, having, a contactless displacement sensor which outputs a displacement measurement signal as measuring a displacement of a turbine moving blade in a rotation axis direction, a blade top position identifying device which outputs a blade top position identification signal to identify a top position based on a distance between the contactless displacement sensor and the top position of the turbine moving blade as receiving the displacement measurement signal output from the contactless displacement sensor, and a blade vibration calculating device which calculates vibration amplitude and a vibration frequency of the turbine moving blade based on temporal variation of the distance between the contactless displacement sensor and the top position of the turbine moving blade as receiving the blade top position identification signal output from the blade top position identifying device.

Abstract: According to the embodiment, there is provided a blade vibration measuring apparatus, having, a contactless displacement 5 sensor which outputs a displacement measurement signal as measuring a displacement of a turbine moving blade in a rotation axis direction, a blade top position identifying device which outputs a blade top position identification signal to identify a top position based on a distance between the contactless displacement sensor 10 and the top position of the turbine moving blade as receiving the displacement measurement signal output from the contactless displacement sensor, and a blade vibration calculating device which calculates vibration amplitude and a vibration frequency of the turbine moving blade based on temporal variation of the distance 15 between the contactless displacement sensor and the top position of the turbine moving blade as receiving the blade top position identification signal output from the blade top position identifying device.