| 摘要 |
PURPOSE:To detect trouble difficult to detect heretofore by a method wherein the drive signal from a signal generation means and the detection signal from a detection part are subjected to fast Fourier transform and coherence relation is calculated on the basis of the converted signals and a vibration testing apparatus is inspected on the basis of the calculation result. CONSTITUTION:A signal generating part 4b outputs a signal for driving an exciter 2a as the function x(t) of a time (t) and an A/D conversion part 5b converts the analogue responsesignal of acceleration from a sensor 3a to output the function y(t) of the time (t) while a fast Fourier transform part 5c applies Fourier transform to the functions x(t), y(t) to output the functions X(f), Y(f) of frequency (f). An inspection part 6b calculates a coherent function (formula I) on the basis of the functions X(f), Y(f) from the transform part 5c with respect to all of frequencies to be inspected to calculate a mean value and the result is displayed on a display part 7b. Therefore, the transform part 5c and the inspection part 6b inspect the mixing of noise and disconnection of a signal transmission system to display the inspection result and, after the normality of a vibration testing apparatus is confirmed, an actual vibration test is performed. |
