A diagnostic device for analyzing a state of a rotating machine that is operated under various rotational speeds, wherein the diagnostic device comprises: - a measurement unit , and - a control unit , wherein the measurement unit is configured to determine a signal having a frequency that changes with respect to the rotational speed of the rotating machine, wherein the control unit is configured to analyze the signal determined by the measurement unit , wherein analyzing the signal comprises: - dividing the signal into a plurality of windows , - extracting a resampling indicator from the signal for each window , wherein the measurement unit is a vibration sensor or a current sensor and wherein, in the case in which the measurement unit is a current sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined N-th harmonic over all windows, and a frequency value of the predetermined N-th harmonic in the particular window or, in the case in which the measurement unit is a vibration sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined frequency component over all windows and a frequency value of the predetermined frequency component in a particular window , - resampling the signal for each window by multiplying a number of original data points of each window by the resampling indicator , - generating a resampled overall signal by joining resampled signals of each window. wherein the diagnostic device comprises: - a measurement unit , and - a control unit , - a measurement unit , and - a control unit , wherein the measurement unit is configured to determine a signal having a frequency that changes with respect to the rotational speed of the rotating machine, wherein the control unit is configured to analyze the signal determined by the measurement unit , wherein analyzing the signal comprises: - dividing the signal into a plurality of windows , - extracting a resampling indicator from the signal for each window , wherein the measurement unit is a vibration sensor or a current sensor and wherein, in the case in which the measurement unit is a current sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined N-th harmonic over all windows, and a frequency value of the predetermined N-th harmonic in the particular window or, in the case in which the measurement unit is a vibration sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined frequency component over all windows and a frequency value of the predetermined frequency component in a particular window , - resampling the signal for each window by multiplying a number of original data points of each window by the resampling indicator , - generating a resampled overall signal by joining resampled signals of each window. - dividing the signal into a plurality of windows , - extracting a resampling indicator from the signal for each window , wherein the measurement unit is a vibration sensor or a current sensor and wherein, in the case in which the measurement unit is a current sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined N-th harmonic over all windows, and a frequency value of the predetermined N-th harmonic in the particular window or, in the case in which the measurement unit is a vibration sensor, the resampling indicator is a ratio of a maximum frequency value of a predetermined frequency component over all windows and a frequency value of the predetermined frequency component in a particular window , - resampling the signal for each window by multiplying a number of original data points of each window by the resampling indicator , - generating a resampled overall signal by joining resampled signals of each window. <EOS>