In a nut shell: I have two sets of data - 1 set measured by myself and another corresponding set measure by a lab. I want to use these two sets of data to get a calibration / correction factor for my method (as the lab uses a different method)

I have completed a scatter graph to get the equation of a line and have a r value of 0.83. I have also averaged the difference between my results and the lab results and got a +2.2 on my results compared to the labs.

I am right to assume that this value (the averaged difference between the data sets) is the most robust way of calculating a correction / calibration factor?

Any help would be greatly appreciated.

Kind regards,