Rene,
Thanks for the info, I will surely try it. As to the harassment, I'm
in your camp; I prefer more resolution, but would not say it's
absolutely necessary to someone on a limited budget.

Calibration is much more important than resolution, especially with a
pH meter. I used 0.1 resolution for years and was satisfied with the
results. (And I used it for everything...)
Regards,
Joe



(Rene) wrote in message . com>...
> Inherited one of those pH sticks, sensitive to +/- 0.05, from Whatmann
> but very much like the pHeps from Hanna. Unfortunately, the two point
> calibration failed as the buffer 4 was too much out of line to get it
> working properly (even after a soak for a couple of days). For
> reference, taking batteries out and in again, buffer 7 read like 6.7,
> buffer 4 read 5 and buffer 10 read 9.
>
> Soaked it in 3 M KCl (ca. 22.5 g potassium chloride/100ml) for a 2
> weeks, the calibration was spot on. Also, without calibration, buffer
> 7 read actually 7.0, basically saying that the electrode was
> completely unbiased, or in equilibrium!
>
> Will never store my electrodes in anything else anymore!
>
> Before any harrassment starts about sensitivity issues surrounding the
> use of +/- 0.05 or 0.1 pH pens, I hasten to say that I use the pens
> only for TA titration of red wines, where I found it hard to determine
> the end point either blackish or very black.
>
> Rene.