On 3 May 00, at 0:08, Alice Campbell wrote:

> Perhaps a better approach to approximating pH would be to
> measure dissolved carbon dioxide.  Evaporation is a big
> problem in vessels open to the atmosphere--as water
> evaporates, salt concentrates, and the conductivity increases
> independent of pH changes.  A similar problem occurs in
> measuring soil moisture.

Alice,

I'm just curious: have you try to measure soil moisture using a
microwave moisture - meter ? This problem will be avoided .

Vasile


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Surducan Vasile, engineer
mail: vasile@l30.itim-cj.ro
URL: http://www.geocities.com/vsurducan
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