Hi Daisi,

in metrology precision is defined as the closeness of agreement between indications or measured quantity values obtained by replicate

measurements on the same or similar objects under specified conditions. This implies that the precision is not just depending on your instrument (as such data from manufacturers are strickly speaking of no value). A way to estimate the precision of. given measuring setup is to perform repeated measurements and evaluate the 'spread' in the results. Further be careful not to mix precision with accuracy or trueness of a measurement. See this link for a full description: https://www.bipm.

org/documents/20126/2071204/JCGM_200_2012.pdf

kind regards

Francois Clemens

Dear Daisi,

The traditional way to make these determinations is through the calculation of reliability and validity measures. There are hundreds of articles and books on how to do this and depends directly on the type of instrument that is being used. It should also be noted that any unreliability and invalidity will eventually work its way into your results by inflating the error terms in your analyses.

Jim McLean

The expression of measurement results must be consistent with the uncertainty associated with it. For intermediate results, higher precision is not very relevant, but the expression of results must be consistent with its associated uncertainty, expressed with two significant digits.

https://www.bipm.org/documents/20126/2071204/JCGM_100_2008_E.pdf

Hi

Normally rule of thumb 1/10 is required but somewhere critical industry,semiconductor, no system good enough 1/10.

Then over 1/4 , i think enough presicion. Thanks