【转帖】rss correction factor for tolerance stack-up analysis

yang686526

rss correction factor for tolerance stack-up analysis
all,
i came across an equation for a correction factor for rss tolerance analysis and was wondering if someone here could ellaborate on it for me. i have typically used a 1.5 times the rss tolerance stack type of adjustment as compared to using a worst case tolerance stack. but, a customer recomended i use a modified correction factor instead of the 1.5 times the rss using the following equation:
{.5*(rss-wc)/[rss*sqrt(# of dimensions)-1]}+1
where rss is the root square mean of tolerance stack-up and wc is the worst case tolerance stack.
the correction factor computed when then be multiplied by the rss of the data to find the adjusted rss. i was wondering where this equation came from so i could use it for other future programs... thanks
j-mo
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