# Magnetic Field Penetration Depth in Various Materials and Applications
## 4 Discussion  
The application of Equations (6) and (7) has led to confusion regarding the units of measurement since, when substituting values, the simplification of units is not always correct. In some cases, the penetration depth \(\lambda\) ends up being expressed in meters per second, as if it were a velocity, instead of meters. Such inconsistencies can not only lead to experimental errors but also affect the theoretical interpretation of the results. While the International System of Units (SI) provides a rigorous framework based on the decimal metric system, the evolution of quantum standards has redefined measurements in terms of fundamental constants, ensuring greater precision and reliability in advanced scientific applications. In this context, it is crucial to analyze how the equations used align with these modern definitions to avoid errors in the interpretation of physical \begin{table}
\begin{tabular}{l l} \hline \hline
**Material Driver** & **ppB \(\lambda\) (mm)** \\ \hline Copper & 10.31 \\ Aluminum & 13.45 \\ Titanium & 51.58 \\ VT6 (ECB) & 79.47 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Depth \(\lambda\) (mm) in common conductive materials. Figure 9: Penetration depth of (\(\lambda\)) in type I superconducting materials. quantities and their application in superconductivity and other research fields [77; 78]; however, this approach maintains the original idea, but with more emphasis on the problem, its impact, and the relevance of unit systems in science and technology. Agreeing with [79], external environmental elements can influence the electromagnetic waves emitted by a generator, causing attenuations when interacting with structures. This effect should be considered when assessing the penetration range of the magnetic field. This is consistent with what is mentioned in [80], where the signal-to-noise ratio improves at higher frequencies, but magnetic impurities in cement widen the lines, reducing the resolution at higher magnetic fields. We affirm the view expressed in [81] that devices exist that detect parallel magnetic vortices with nanometer resolution, accurate depth, and low field induction, operating in applied fields up to 200 mT. We agree with the claim in [82] that at a zero temperature, the magnetic penetration depth (\(\lambda\)) varies linearly with the magnetic field, reflecting the non-linear Meissner, although the experimental evidence is uncertain due to external factors fluctuating in milliseconds, as also mentioned by the authors of [83]. As stated by the authors of [84], interlayer interactions in superconducting heterostructures are crucial, as they affect the current distribution at the interfaces. This modifies the response to external currents, magnetic fields, and electromagnetic stimuli, complicating the overall behavior of the system. In veracity [2], the optimized performance of RF and AM atomic magnetometers at low frequencies allows for the EMI interference to be measured with high sensitivity, which is useful for detecting concealed weapons or underground imperfections, albeit with limitations in certain applications. The penetration depth of ultraviolet radiation increased when the stratum corneum was thinner. This experiment improves the understanding of the wavelength and penetration of light into the skin, which could optimize light-based diagnostic and therapeutic approaches for dermal diseases [85]. However, it is also necessary to investigate the possible side effects of the magnetic field when used in species treatments and in prescriptions for muscle diseases or biological tissue [86]. Regarding electromagnetic field propagation and the skin effect [87; 88], these principles will depend on a variable known as the wave propagation frequency. However, for alternating electromagnetic fields, higher frequencies will decrease the penetration depth due to the skin effect. The research articles reviewed focus mainly on materials such as conductors, semiconductors, superconductors, insulators, and natural materials.