"ss" -ag> wrote in message
...
> OK - I don't want to make a long story longer - but here goes.
> I have a Hanna Piccolo - its been fine for about 3 years . I store it in
> storage solution.
> I have recently cleaned it with a cleaning solution. I also replaced the
> batteries.
> It calibrates fine at 7.00ph and at 4.00ph. It measures wine ph fine.
> ... but when I try to use it to measure TA - i add NaOH solution in
drops
> and watch the
> ph rise until it reaches 7.23 - above which it will not register - no
matter
> how much NaOH I add.
> This is a recent development - and it worked fine on my last batch of wine
> in September.
>
> So the question is - does this behaviour sound familiar?
> - is the electrode pooched?
> - are there any homegrown mixtures of high ph - ie. alkaline which I
>could calibrate or at least check over 8.0.

Steve,
If your are using a 0.1 N sodium hydroxide solution for TA measurements, the
pH of that solution is 13. If you are using a 0.2 N solution, it's pH is
13.3.
Lum
Del Mar, California, USA

> snip.........