Hi Rik and others,


>  measuring DC resistance is not very meaningfull

Absolutely! The soil charges up.
It's quite fun to do. Take your multimeter into the garden, put it on the Ohms 
range and put the meter prods into the soil some distance apart.
The resistance starts quite low then rises.
When it's tailed off, or you've got bored, switch your multimeter to the Volts 
range.
You see a voltage from the secondary battery you've charged up in the soil; it 
fades to zero volts quite soon.


73,
Chris G4OKW
 
-----------------------
Dr Chris Trayner
School of Electronic & Electrical Engineering,
The University of Leeds,
Leeds LS2 9JT, United Kingdom
Tel: +44 113 34 32053
Fax: +44 113 34 32032