Neptune Conductivity Calibration Solution (53.0 mS)

Base on some reading the 35 solution make it off by 1.5 +- like most refractometer. I calibrate with Neptune conductivity 53 solution, and is find.
I have dificulty for year because of that. Event ICP test confirme that but I never make the link to the Hanna salinity tester, I now use this and is perfect.
ICP back checked!