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Excessive vibration of structures supporting optical equipment degrades equipment performance. Manufacturers'' maximum allowable vibration criteria are frequently insufficient for determining the acceptability of a vibration environment. Criteria development and effective dissemination are critical issues which must be adequately addressed. Criteria development must include consideration of dynamic characteristics encountered in building structures, mechanisms resulting in degraded performance, and analysis methodology most suitable for quantifying the threshold of degraded performance. Published criteria must explicitly state the required vibration analysis methodology and measurement units of RMS, O-pk, or pk-pk. This is crucial because quantitative results of vibration analysis can vary significantly with different analysis methodologies, thus influencing acceptability of the vibration environment relative to a given criterion. An Institute of Environmental Sciences working group composed of microelectronics manufacturers and researchers, FHA and other vibration consultants, has drafted a recommended practice for measuring and reporting vibration and developing criteria (''RP-24''). This paper provides a brief introduction to the IES draft Recommended Practice RP-24, ''Measuring and Reporting Vibration in Microelectronics Facilities.'' Examples are provided which illustrate quantitative effects of variations in vibration analysis methodologies.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
