I know this is not the best place to post, but I'm desperate. I can't get ahold of Reichert for technical support (I have never talked to anyone from there for tech support the several times I have called over the past year|10-15X) and no returned calls.

I need to be compliant with USP, which says that the refractometer (Abbe II plus) needs to be calibrated with a standard from Reichert.

I calibrated to DI water a few weeks ago and it's still in calibration for that, but now I'm trying to calibrate this oil with an RI of 1.51432 @ 25C. The problem is when I can see the X and the shadow bar in focus, I can't adjust the shadow bar since the adjustment screw is blocked by the knob that puts it in focus.

So how can I calibrate??

The solutions we will be testing are dimethicone solutions and BAC solutions. They need to make sure the %solids meets spec.

Any help would be great.