Author: Lau, Wing-keung
Title: Machine condition monitoring by time : frequency analysis on start up and shut down signals
Degree: M.Sc.
Year: 2003
Subject: Hong Kong Polytechnic University -- Dissertations
Pumping machinery -- Noise
Pumping machinery -- Vibration
Department: Department of Building Services Engineering
Pages: ii, 85 leaves : ill. (some col.) ; 30 cm
Language: English
Abstract: This dissertation describes machine condition monitoring by vibration signatures during start up, steady state and shut down. Short Time Fourier Transform (Tang 2000) will be carried out in the analysis. In the present study, it is to use the signal obtained from the start up and shut down processes to undertake the diagnostics. The higher jerking and accelerating / decelerating motion in the machine components may produce signals, which though non-stationary, will magnify any fault in the machine system. Vibration signal of chilled water pumps and driving motors were captured under normal start up, steady state running and shut down condition. Experimental vibration signatures are compared and discussed for various scenarios. From the experiments, the shut down vibration did indicate machine health status; e.g. difference in shut down time periods and the amplitude distribution profiles.
Access: restricted access

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