Hydrometer wanted

Anybody have one collecting dust??

I think I have two… but I’m not sure where they are. And I think I might have used one to suck brake fluid from a car…

I still see several options on Takealot, for not much more than a courier would cost to send you an old one…

I have one of these: Hella Battery Acid Tester

I’m wanting another one to check this one. (Not to blindly trust one instrument!)

I wouldn’t necessarily consider the two identical ones I have (somewhere) to be particularly well calibrated either. Though it must be said the traditional kind with the glass bulb weighed down with some lead… pretty hard to get wrong. The same one they sell on Takealot.

The Hella one is fairly accurate with its counter rotating dials…
I was hoping for an equivalent old school version (or if I can get a solution with a SG that is known!)