What is the frequency of determination of minimum weight for analytical weighing balance

What is the frequency of determination of minimum weight for analytical weighing balance.
Is it sufficient only during the initial qualification?
Or a periodic determination of minimum weight is required?
If period determination of minimum weight is required, what is the frequency?

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For analytical balances , the minimum weight depends on repeatability test result (Standard Deviation) as illustrated in USP 1251
It is typically done once a year as mentioned in OMCL Annex 8

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When you determine SD of analytical balance during repeatability test , directly the minimum weight can be calculated using minimum weight formula present in USP chapter 1251

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Note that it is recommended to apply a safety factor (2 by default) when determining minimum weight as illustrated in Mettler Toledo GWP.