Reliable Proof/Tralles Hydrometer

[Uncle B]

Greetings, all,

Quick question - does anyone have an online source for a reliable proof/tralles hydrometer?

I have one that I used for a while, but after a while thought the paper in it might have slipped. Purchased another, tested them against each other, and found about a 1%/2 proof difference. Not too big a deal. But then I tested both in a commercial vodka, and both read roughly 86 proof in an 80 proof bottle. (Lesson learned - check your meters!)

Anyway, would love a reliable source if anyone has one they've checked and are happy with.

Thanks!

Uncle B