Table III of the 1957 Neher-McGrath paper

[morgan3520]

Is anyone familiar with how to use Table III. Skin Effect in %/ in Solid Round Conductor and in Conventional Round Concentric, Strand Conductors, 100 F(x), Skin Effect % of the 1957 Neher-McGrath paper?

 

[synchro]

Get x_s from equation 22 using the DC resistance per foot of the conductor and the k_s factor provided in Table II. for concentric round conductor construction which is 1.0. Then in Table III. read the skin effect's contribution to the total resistance as a percentage of the DC resistance for that specific value of x.
For example, if x_s was 2.14 then from Table III. the skin effect would contribute 10.05% of the DC resistance.
Consider this result in Fig. 1, where for F(x) = 0.1 (i.e., a 10% skin effect), one can read off R_dc /k ≈ 10. And then from equation 22, x_s = 6.80 / √(R_dc/k_s) = 6.80 / √(10/1.0) = 2.15 which is consistent with the value of x_s that was picked above.

 

[morgan3520]

Get x_s from equation 22 using the DC resistance per foot of the conductor and the k_s factor provided in Table II. for concentric round conductor construction which is 1.0. Then in Table III. read the skin effect's contribution to the total resistance as a percentage of the DC resistance for that specific value of x.
For example, if x_s was 2.14 then from Table III. the skin effect would contribute 10.05% of the DC resistance.
Consider this result in Fig. 1, where for F(x) = 0.1 (i.e., a 10% skin effect), one can read off R_dc /k ≈ 10. And then from equation 22, x_s = 6.80 / √(R_dc/k_s) = 6.80 / √(10/1.0) = 2.15 which is consistent with the value of x_s that was picked above.

View attachment 2563054

Thank you.