Question on gravity readings.

[Ajes]

Hey.
I got my hands on a standard SG hydrometer (brewferm), a precision hydrometer for 0-10 plato (alla france). I'm trying to compare them, and calibrating my ispindel.

However, I get a weird reading today (all at 22 degrees C):
The SG hydrometer reads about 1.012
however, the other hydrometer reads 5,7 plato (corrected from 5,6 @ 22 C).
So I'm confused - I thought the plato hydrometer would be more presice than the other hydrometer...
What am I missing?

 

[Ajes]

AAAAnd the answer is:
use a taller 250ml glass, so the hydrometer does NOT rest on the bottom.
/slapface