Where does the 1.3% machine error factor into absolute error calculations?

[Steve619]

In writing up on errors and knowing the error of the machine used (as told by the technician) as being 1.3%
where I have a table of theoretical and measured values,
The absolute error the difference between the theoretical and measured value, but where does the 1.3% error come into play?

And what type of error is it?

 

[BvU]

Hello Steve,

Could you give a bit more context ? What's this about ? And perhaps a few examples of measured and theoretical values ?