Envelope-to: dave@picks.force9.co.uk
Delivery-date: Mon, 14 Nov 2005 17:10:20 +0000
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From: "Hugh M0WYE" <m0wye@thersgb.net>
To: rsgb_lf_group@blacksheep.org
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Date: Mon, 14 Nov 2005 17:04:42 -0000
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Subject: LF: Re: How measuring Ground conductivity ?
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Hi Uwe,
It is usually recommended to avoid harmonics of the power line frequency. 
This avoids mains earth-return currents affecting the reading.

Also a 4 probe method, with two outer probes delivering current, and inner 
ones measuring voltage in the so called "Wenner" configuration is usually 
used.

However I got similar readings to you - around 10 ohms - with moist, garden 
soil.

I found the most repeatable readings were when one current and one voltage 
probe, 1m apart, were seperated by 10s of meters from the other pair - as is 
used for archeological ground resistance surveys.

73
Hugh M0WYE


----- Original Message ----- 
From: "Uwe Wensauer" <uwe.wensauer@gmx.de>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, November 14, 2005 4:31 PM
Subject: LF: How measuring Ground conductivity ?


To discuss

Measure ground conductivity.


I placed two stainless- steel rods ( 3mm dia ) whithin a distance of  7 
Meters apart abt 80cm deep into soil

Powered with 50 Hz.
In series with the electrodes is a 10 Ohm resistor. In order to measuring 
current, I measure the voltage drop across resistor.

Depending on weather I got 8 Ohm / m = 125mS

Is this measurement setup ( proceeding ) correct ?

Please correct me.

Uwe, DK1KQ