DIY Refractometer calibration fluid

[Randy Holmes-Farley]

Thank you for that. It’s a DD H2ocean refractometer. Is that what you would expect from that one?

That one claims to be a true seawater refractometer. If perfectly made and perfectly calibrated with a perfect 35 ppt standard, it would read zero and 35 ppt correctly.

If using a perfect 35 ppt standard, you need not rely on it being made correctly to read 35 ppt, but the standard does need to be correct. It may not be.

 

[Randy Holmes-Farley]

The milwaukee digital ones are the same....calibrate to zero with rodi. So i did that, then measured my DIY standard, and got 1.027.

Which is within spec. :)

 

[Randy Holmes-Farley]

Their write up is confusing and I’d ignore it. The whole temp discussion has more potential to be misunderstood than helpful.