$x_p$ should not exceed 2.8 for an accurate estimation of the proximitiy effect factor $y_p$.

Symbol
$x_{\mathrm{p}}$
Unit
-
Formulae
$0.000894427190999916 \sqrt{\frac{f k_{\mathrm{p}}}{R_{\mathrm{c}}} \pi}$
Related
$f$
$R_{\mathrm{c}}$
Used in
$y_{\mathrm{p}}$