every body ! kindly ;show me the way that I can design my own earth tester,I need to a circuit diagram.
earth tester
Dec 04, 2005
8 Replies
Test for what?
Continuity? Static discharge safe limits? Salinity?
RL
thanks . to measure soil resistivity.
thanks . to measure soil resistivity.
Perhaps the references on this page may be useful:
formatting link
** So you want an electronic soil analyser ?
These Google Groupies are such a hoot.
.......... Phil
How far down into the soil do you want to be able to see?
Do you want a profile or just a single value?
Is your local mains frequency 50Hz or 60Hz?
I'll assume 60Hz
(1) Make a good 30Hz square wave that is isolated from any other earthing. This needs to be about 25V and able to output several amps.
(2) Make a synchronous detector circuit. Followed by a filter that cuts off at about 0.5Hz.
(3) Sync the detector (2) to the generator (1) via an opto isolator.
(4) Drive large spikes (1cm Dia 20cm long) into the soil like this
ASCII Art:
---I--- ---V--- ! ! ! ! V V V V
-------------------------------------- Soil
(5) Measure the voltage you get for some known current and apply a "geometry factor" to get the resistivity.
--
kensmith@rahul.net forging knowledge
Whether or not he's on earth. ;-)
Paul Hovnanian mailto:Paul@Hovnanian.com
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Bumper sticker: You\'re too close for missiles. Switching to guns.
Immunity to excessive heating?
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