Ok have the results of comparing my Brix/ ATC refractometer with the instrument at the office. The scientist analysis was that the water % was 15.820%.
My brix was 16% or a little over 16% depending on the angle you held it at. He said that obviously having a computer/ software based digital readout is easier than using one that needs to be focused is easier to read.
They calibrate much like the Brix does first with distilled water to null or %78.8 and then use the calibration oil and fine adjust at %78.8. I will tell you that getting a sharp line with the distilled water is harder than the calibration oil. The oil is very clear. Honey is very sharp and easy to read. Must have something to do with the density of the fluid.
Anyway, I am very confident that my e-bay purchased meter is accurate. And I left him the jar of honey

he said stop by anytime! Nice!
looks like mine is within the .5% accuracy they claim, so I guess I will just make sure I am under the margin of error and I will be good!
Opinion?