[TowerTalk] Fwd: Tower base/Ufer ground

[Roger (K8RI) on TT]

On 5/17/2014 11:27 PM, Jim Lux wrote:
> On 5/17/14, 6:11 PM, Drax Felton wrote:
>> What is the conductance per inch of concrete in mho's ?
>>
>>
> http://www.k1ttt.net/technote/concrete.html
> 10-50 mS/m

Shouldn't the medium be in cubic units?

With concrete it varies widely, but when you get that large, it's the 
surface area that dominates.

Resistivity, the inverse of conductivity is in cubic units. 
Unfortunately the "new" Si units are no longer meaningful and require 
conversions.
Typically Resistivity is measured in CC as would Siemens(mho's), but 
much depends on the size of the samples. Measuring CC is a whale of a 
lot easier than cubic meters (the probes are a whole lot easier to make 
and use

73

Roger (K8RI)