I'm trying to understand what is the maximum deviation between two measurement methods. I read this on a paper on which there is a comparison between two devices to measure pH.
The sentence on the above paper is: "Maximum deviation was found to be 1.2% or 0.08 pH between two measurement methods.".
Online I found only a definition related to a single set of measurements (http://phys.columbia.edu/~tutorial/estimation/tut_e_2_3.html):
$$Maximum \,\,\, deviation=max \,\, measured \,\, value - average \,\, value$$
Thank you for your help.
I think in your case the maximum deviation between two measurement methods is the maximum difference of their measurements for the same input sample.
Thus if the two methods agree or nearly agree on most samples, but on one sample differ by a large value 1.2%, then the "maximum deviation between two measurement methods" is that 1.2%.
It is a simple concept.