How to Determine Inherent Error?

How to Determine Inherent Error?

How do I go about this? For instance, I could observe the measured masses of a block of wood. I have 10 measurements of the mass using the same digital scale. Say for instance I get an average of 10.005 grams.
I can determine the standard deviation with the data set. Or I could determine the percent error for each of the measurements by using (observed-avg)/avg
I just am lost as to determine the inherent error caused by the machine… How do I do this?