hydrometer's pattern of inaccuracy?

[Kigs]

I know hydrometers are not always accurate compared to refratometers, but if they are inaccurate, do they tend to read lower or higher? or is the outcome always different?

 

[alan214]

From what I've read on RC, they tend to read low but that's probably not a 100% certainty.

 

[boxfishpooalot]

My experience was lower and higher. Fwiw any small air bubble on the arm will cause faulty higher readings. Also if you soak the arm in pure vinegar, the arm will read lower permanently. The vinegar will change the density of the plastic.

But above all I think they are semi-accurate if used properly with doing and not doing the above mentioned things.

 

[Kigs]

ah. got it. thanks guys.