NV Dynamics was retained by a well renowned semiconductor manufacturing firm to assess vibration severity levels and to comprehend the contribution of vibration from the emergency Diesel Generator (DG) and other such sources on the equipment platforms of the vibration sensitive machines.
Based on the customer requirements, four (4) key locations were identified on site and a pair of ultra-low frequency vibration transducers were mounted in horizontal and vertical directions at each identified location. The transducers were then connected to a multi-channel data acquisition system and subsequently vibration data was recorded at all the four locations with the DG in OFF and ON conditions.
Data processing included the conversion of vibration acceleration data into vibration velocity data by integration. A bandwidth of 1-80 Hz is considered for processing the data using linear averaging to obtain 1/3rd octave band graphs. The obtained data was then compared against internationally accepted vibration criteria curves - VC-B and VC-C, which represent the permissible limit for vibration sensitive equipment under consideration.