求翻译：由图4可以看出：当频率很低时，感应电流及其产生的二次磁场的实分量近似与频率的平方成正比增加；当频率趋于无穷时，它趋于一个渐近值。是什么意思？

It can be seen from Figure 4 : When the frequency is low , and the real component of the induced current generating a secondary magnetic field is approximately proportional to the square of the frequency is increased ; when the frequency tends to infinity , it tends to be an asymptotic value.

From figure 4 it can be seen that when the frequency is very low, and the sensor current and the resulting 2 magnetic field at the real-time component close to the frequency is proportional to the square; when the frequency tends to infinity, it tends to a gradual value.

May see by Figure 4: When the frequency is very low, the induced current and produces two magnetic field real components are approximate with the frequency square are proportional the increase; When the frequency tends to infinitely, it tends to an asymptotic value.

Can be seen from Figure 4: when the frequency is very low, the real component of the induced current and the secondary magnetic field increased approximately proportional to the square of the frequency when the frequency approaches infinity, it tends to an asymptotic value.

正在翻译，请等待...