Penetration depth

The penetration depth is used as the units character of the assets of an object, of substances or of waves to penetrate an object or matter, or as a property of the object, a penetration to resist. It is usually related to a standardized penetration process and determined by a comparative measurement method.

Ballistics

In ballistics, the depth of penetration of a projectile weapon with an attack sample to a block of standard material (eg, ballistic gelatin) is determined. This measurement method is mainly used in forensics to determine the shooting distance can.

Electromagnetic waves

Wherein the penetration depth of the electromagnetic waves is the point at which an electromagnetic wave in the penetration into a medium, only a still - tel (about 37 %) corresponding to the output amplitude.

The notion found, inter alia as a London penetration depth (London equation), penetration depth of an evanescent wave (see ATR spectroscopy) and the skin effect application.

Geophysics

In various geophysical methods, the penetration depth is a limiting factor in the analysis of structures inside of the earth. Here are methods in which the Earth's interior is radiated through the excited waves.

In addition to electromagnetic methods such as ground penetrating radar or magnetotelluric the term is also used in the geoelectric and in terms of seismic waves in seismology and seismic active. The penetration depth is dependent on the frequency of the wave, however, is limited by the distance from the source to the instrument and the associated beam path.

Materials

For materials, the penetration depth is entering a measure of the ability of a liquid into a material. In the impregnation is of course desired that the impregnating agent has a largest possible depth of penetration. When not commercially available today film-forming paints and coatings, because of the increased consumption, on the other hand. The high penetration of pure linseed oil and pure linseed oil paint is in turn a prerequisite for their conservation status.

Material testing

The material testing different measurement methods are used in which the basis of the penetrability of a comparison body in the material whose hardness is determined. The deeper is the depth of penetration, the softer the fabric. However, only values ​​are compared, which were determined by the same method of measurement.

The following measurement methods are widely used which work with the measure of the penetration depth:

• Brinell hardness test
• Vickers hardness test (hard metals)
• Knoop hardness test (hard metals)
• Rockwell hardness test (different test specimens)
• Hardness test Shore (some also suitable for non-metals, such as elastomers and FRP)