Table 2 Table of the nineteen configurations in Fig. 4 with its impedance equation (11) and the electrode involved for each role.

1

\(Z_1 = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_1}- \frac{1}{d_2}\right) \)

11

21

31

41

2

\( Z_2 = \frac{{\bar{\kappa }}}{K}\left( \frac{1}{d_1}-\frac{1}{d_7}-\frac{1}{d_2}+\frac{1}{d_5}\right) \)

11

21

31

42

3

\(Z_3 = Z_2\)

11

21

32

41

4

\(Z_4 = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_1}- \frac{1}{d_7}\right) \)

11

21

32

42

5

\(Z_5 = Z_2\)

11

22

31

41

6

\( Z_6 = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_5}- \frac{1}{d_2}\right) \)

11

22

31

42

7

\(Z_7 = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_5}- \frac{1}{d_7}\right) \)

11

22

32

41

8

\(Z_8 = Z_2\)

11

22

32

42

9

\(Z_9 = Z_2\)

12

21

31

41

10

\(Z_{10} = Z_7\)

12

21

31

42

11

\(Z_{11} = Z_6\)

12

21

32

41

12

\(Z_{12} = Z_2\)

12

21

32

42

13

\(Z_{13} = Z_4\)

12

22

31

41

14

\(Z_{14} = Z_2\)

12

22

31

42

15

\(Z_{15} = Z_2\)

12

22

32

41

16

\(Z_{16} = Z_1\)

12

22

32

42

17

\(Z_{17} = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_4}- \frac{1}{d_1}\right) \)

11

12

21

22

18

\(Z_{18} = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_4}- \frac{1}{d_2}\right) \)

11

12

31

32

19

\(Z_{19} = \frac{2{\bar{\kappa }}}{K}\left( \frac{1}{d_4}- \frac{1}{d_3}\right) \)

11

12

41

42