---Ursprüngliche Nachricht---
I´am mesuring ground conductivity over almost 1
year regularly
today it was 15,6 Ohm / m ( measured with 16Volt@
50Hz )
I try to built a measuring device with other
frequency , somthing odd ( no multibles from 50Hz, thinking about 111 Hz -
)
and automatic daily measurements ( at present times
done manually)
Would like to discuss about it
Uwe, DK1KQ
Overture to the
following:
in the area of our local community citizens
are upset because
there have been falls of
ground surface (Erdfall) some
two or
three meter deep opening caves of two to four cubic meter.
scientists do not know what
the reason is. they belief (!)
lime
has been washed
out during hundred of years and the abt one meter
thick earth above the
cave breaks without any warning. is that
phenomenon known
elsewhere?
the community self government asked the authority to find out
whether there are more "caves"
around.
they came and
tried it by measuring the earthresistivity.
method: they ram
standardized
metal rods into the surface
and connected 100V DC(!)via a
measuring equipment. the
technicians taking those measurements in the vecinity of
my yard told me the result:
110
Ohm/m.
I
was not surprised because my own tests using AC (50Hz)
showed 113,7 Ohm/m.
OK., it does not state
that it must be 113 Ohm/m
in a 136kHz
aerial
system .
BTW.they do use a pulsemodulated elf
carrier and the echo
method if in search of
p.e. oil.
regards
Uwe/dj8wx
