Fwd: Re: SOWACS Fwd: gypsum block sensor

[Cliff Hignett]

Cliff Hignett writes to the sowacs list:
===8<==============
In response to gypsum block query - You do not say what the environment
is, perhaps the block is too large and is taking time to drain .    Is 
polarisation a possibility  - are you using AC voltages?

cliff.hignett@soilwater.com.au

Bruce -owner of sowacs wrote:

>Pretty mugwaze writes to the sowacs list:
>===8<==============
> I am doing a project on an automated irrigation
>control system I have made two gypsum blocks with
>electrodes which are 1.2cm and 0.6cm apart. The 1.2cm unit
>is not changing much in voltage - it reads the same
>value for almost two days, but the other one is
>changing from 0.1v to about 0.3v. I have put the
>block in series with a resistor so that a potential divider
>can be used.
>What do you think could be the problem with the other block (1.2cm)
>

===8<==============
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