I am trying to calculate time weighted standard deviation on PI data. I am using formula below. My time weighted average result matches the PI summary average but not the standard deviation.

Is Pi using any different way for standard deviation calculations.

Hi Priyanka,

Sorry, this post of yours "fell among the cracks".

Could you tell us which PI products you are using to calculate the time-weighted standard deviation? Are you coding using the PI-SDK? Or maybe PI DataLink? Please let us know.