[TowerTalk] Clamp on ground resistance meter

[John Simmons]

Can I infer that a 3-legged tower with 3 ground wires, each with 
multiple rods would have a total ground resistance of each wire's 
resistance in parallel? I.E. 1/R wire1, etc?

-de John NI0K

Grant Saviers wrote on 10/2/2019 3:46 PM:
> The loop you want to measure is the single rod through the earth to 
> multiple rods or a very low R ground such as a building Ufer.
>
> Start with two rods connected with a wire, put the meter on that wire, 
> measure R. The assumption is that each rod has a resistance of R/2. 
> When you install the 10th rod the assumption is that the nine already 
> placed, connected together, and connected by a single wire to rod #10 
> have a much lower parallel resistance than the new rod. Of course 
> there is some residual error, but if you go back and measure them one 
> at a time, one against nine, you will get close approximate 
> resistances of each rod.  Then these values can be computed as 
> parallel resistances for a close approximation of the net ground field 
> resistance.
>
> This is why a star layout of rods and connecting wires that looks like 
> a vertical antenna radial field is easy to measure, one rod at a time. 
> OTOH, if you have a perimeter wire, the meter will measure the wire 
> resistance of that loop.
>
> Plus such a layout is the way to minimize the paralleled inductance.
>
> Grant KZ1W
>
> On 10/2/2019 11:59 AM, Wes wrote:
>> Hmmm.. Every other reference I see about using one of these says that 
>> a loop is required.
>>
>>
>> On 10/2/2019 11:00 AM, Bryan Fields wrote:
>>> On 9/29/19 2:51 PM, Julio Peralta via TowerTalk wrote:
>>>> Does anyone have any experience using a clamp on ground resistance 
>>>> meter?
>>> Yes, they work well.
>>>> I bought one to use to help with my grounding project but don't 
>>>> have any
>>>> experience using this type of meter. Any advice would be appreciated.
>>> Ensure it's calibrated every time you use it.?? You should ensure 
>>> it's not
>>> measuring a loop, that will give errors.?? Single point or off a 
>>> master ground
>>> bar feed is the right place to measure it.
>>>
>>> I have this model:https://www.amazon.com/gp/product/B01N7FSF6N
>>>
>>> Was a steal for 300 dollars.?? I've used it at my home and numerous 
>>> sites to
>>> ensure the building ground is sufficient.
>>>
>>> 73's
>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk