I used my Hanna buffer sachets 4.01 and 7.01
Meter gave the same error on calibration.

I changed the probe

Now it calibrates fine with no errors....

I also bought some pH storage solution. Hopefully I get more then 2
years on this probe.


Borek wrote:
> On Wed, 12 Sep 2007 16:18:53 +0200, RD > wrote:
>
>> They are stable for a pretty long time - afterall, they
>> are buffers.
>
> pH 4 buffers are stable, pH 7 more or less stable, pH 10 buffers are
> unstabel if they are not kept airtight. Once again that's CO2 in action.
>
> But you are absolutely right that it doesn't make sense to look for
> household items, as relatively precise buffers can be bought cheap.
>
> Borek