Uncertainty in measurement larger than tolerance

Rybeck03

Registered
Hello,

I have received a calibration certificate from a vendor for pipette calibration. The tolerance given for range inaccuracy and imprecision is ± 0.600 µl at 100.000 µl. The uncertainty of measurement reported is ± 1.30 µl. Therefore, their uncertainty is larger than the tolerance. Wouldn't all calibration results that are within the ± 0.600 µl be an indeterminate pass? How should I go forward with this? Any suggestions would be gladly received.

Regards
 

dwperron

Trusted Information Resource
Hello,

I have received a calibration certificate from a vendor for pipette calibration. The tolerance given for range inaccuracy and imprecision is ± 0.600 µl at 100.000 µl. The uncertainty of measurement reported is ± 1.30 µl. Therefore, their uncertainty is larger than the tolerance. Wouldn't all calibration results that are within the ± 0.600 µl be an indeterminate pass? How should I go forward with this? Any suggestions would be gladly received.

Regards

The quick reply is to ask for your money back!

You are correct, the result is indeterminate, but since their uncertainty is beyond the bounds of the tolerance they cannot declare whether it was in or out of tolerance.

Give the lab an opportunity to review the results, but if they stand by these results being adequate it is time to seek a new lab.
 
Top Bottom