I have two sets of data, what is the best way to fit one set of data so it most closely matches the other

I have taken two sets of data with two different instruments. We know data set A taken with instrument A is very accurate and precise and that set B, while precise, is not accurate. Thus my data sets might look like this:

Set A: {10, 10.2, 9.9, 10, 10, 9.1}
Set B: {6, 7, 6.5, 5.5, 6, 7}


I want to figure out the best way to "translate" set B so it is comparable to set A. My initial thought is to simply shift set B by some delta (maybe 3.0) but I am unsure as to what the best way to define this delta is. Can I just take the averages of the sets and find the difference? Should I be looking at the mean square error? Should I make a linear fit for both sets and compare the difference values along the lines? I am trying to perform this in excel.

Please let me know if something is not clear, thanks!