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Dear All, If I have two conductors in a homogeneous ground (constant resistivity), parallel to each other and of the same length. each of them has got a transverse resistance to earth. I'd like to find an electrical model to represent the mutual resistance between these two conductors. Is it possible to do this by an analytic approach (and not only by finite elements) ? I was thinking of splitting each conductors into a given number of segments. Thanks for your support. Regards.

Gents, Thanks for your contributions. By fall of potential method, I meant this using 3 électrodes: - E, which is the electrode to be measured - P, which is the potential electrode - C, the current electrode The testing current is impressed in E and returns through C. See attached for illustration. Regards. fall of potential.pdf

Dear All, Suppose I have two parallel conductors of different lengths in a homogeneous soil of resistivity Rho, and separated by a height of H. Is there any existing formula to calculate the mutual resistance (in DC) between them ? With my thanks.

Dear All, I’d like to share an experience with the fall of potential method: if I call E the electrode under measurement (in a square arrangement of approx. 20m), P the inner Potential electrode and C the outer current electrode, I could get a flat curve of the E resistance whilst C was away from E by a distance corresponding roughly to the side of E. I was quite surprised since I thought this distance was too short and I expected a non flat resistance curve since E and C were supposed to couple with each other. Hence a question: can you theoretically get a flat curve when E and C voltage gradients still significantly overlap and, if so, does it necessarily mean that the resistance corresponding to the middle of this curve correspond to the real resistance of E to earth ? Thanks for your lights.

Dear All, Thank you for your respective contributions. I do appreciate ! the reason why I need this function is because I need to integrate it in function of x. Have your codes been typed on Matlab ? Do I need module "Symbolic Math Toolbox" to try your code ? Thanks again and Regards, Cédric

Dear All, I'm trying to find function J(x) shown in attached file. Could somebody help me ? It seems that I don't have the right tool to solve it Thanks and Regards. Série.pdf

Well caught, thank you very much for your support from the beginning. I'll not be involved myself into finite elements, but an engineering student will dot it for me. I've got a licence of CST, do you know this tool ? One last question please : have you got any opinion on the resistor value of my cube edges ? Kind Regards.

Do you know if Comsol also deals with electrical fields ? Is it a freeware software ?

Oh I see, thanks ! Do you personally use these tools, and especially the circuit simulation one ?

I'll try this, thanks. But is Octave-Forge somehow related to Matlab or not ?

Thanks for your reply. Is there any special module to access to this functionality ? I have the basic licence only. Regards.

Dear All, Suppose I've got a medium (like a soil) of a homogeneous and constant resistivity Rho (in Ohm.km). This medium is put into a big cube of 1km side, then giving a km3 of my medium. Now suppose I want to model my cube by an electrical circuit with resistors at each side of the cube. May I state that each resistor will be Rhox4 then ? No suppose I divide my km3 into equal 8 cubes of 500m side each and suppose I still want to model this arrangement by electrical resistors. What should be the value of each resistor/side then if I need that the whole set still corresponds to a resistivity of Rho ? I propose Rhox9/2. Am I right ? For these who know Matlab, can Matlab simulate this kind of 3-D electric circuit with cubes whose sides are resistors ? Is there any special module to perform this function ? Thanks to All.

Dear All, Does somewhat know this software well ? I'm trying to get potentials in the ground but below the surface of the soil, and what I only managed to get so far are potentials on the soil surface. This does not surprise me since this software is intended to calculate step and touch potential for people staying or walking ON the soil, and not for dead people buried in the ground... If Cymegrid cannot achieve this, would CDEGS do the job ? Thanks.

Hello Studiot, Please find attached a sketch, where 3 soil layers have been represented. A current is impressed in P and the goal is to determine the potential of points M1, M2 and M3 with respect to far earth. If my purposes are not clear, please get back to me. Kind Regards. 3 layers.pdf

Hello Studiot, Thanks for your kind contribution. Ideally, I'm after a function of A in order to plot it, knowing that I know between what values (O and Pi) I need to integrate this function. Actually, I asked for the primitive in order to calculate the integral, which is also a function of A, and this is the one I'd like to plot. For your information, this primitive/integral is needed too solve Bessel's equation and function. I'm sorry for the poor quality of my English. Kind Regards.