Pipette Calibration

[Maddy78]

I am responsible for calibrating gilson and eppendorf p20, p200 and p1000 pipettes. Rather than send these off every month I take 20 weight readings at two volumes of water for each pipette. I would like to know what the acceptable ranges (and maybe SD/SEM) for each pipette is at different volumes- eg for a p1000 at 500uL and 1000uL.
Thanks

[jazzlynblu]

It depends on your purpose or use. Typically, in the microbiology laboratory, we accept an error of 0.2-2% depending on the volume measured. (E.g. if the pipette should measure 1000ul of liquid at 20 degree celcius, then the error should not be more than 2ml.) We basically go by a two point rule. The SE can be +-2ul for 1000ul or 100ul, and +-0.2ul for 10ul.