[Eidors Help] help - Non-equal electrode size using ng_mk_cyl_models

[Max v. F. <M.L...@st...>]

Hi,

I am using EIDORS3D to verify some ERT measurement results of liquid-solid mixture flows. I am impressed by the ease of use and think it is a very useful tool.
When constructing a 3D ert sensor, I ran in to a problem.

I use the following code in order to create a cylinder&sensor with the following properties:
0.1m long, 0.02m radius tube, with at 0.05m a 16-electrode sensor. Each electrode is 0.02m long and 0.005 m wide.

%
cyl_shape=[0.1,  0.02 0.003];
elec_pos=[16, 0.05];
elec_shape=[0.005, 0.02 0.001];
mdl=ng_mk_cyl_models(cyl_shape,elec_pos,elec_shape);
%

When creating the model and viewing it via show_fem, it shows that the generated electrodes have different widths. I tried changing the width of the electrodes and playing some with the grid size, but the problem keeps appearing. For different widths (0.002, 0.005, etc) some electrodes become bigger than the set value, some become smaller.  When looking at the forward solved homogeneous voltages, they show discrepanties because of the non-equal electrode distances that result from this.

Is this a known problem? I am not sure if the problem lies with EIDORS or Netgen, or is the mistake with me?

Thanks in advance.

Max
MSc Student at Delft University of Technology