List of body armor performance standards
Of note is the inclusion of special regional threats such as Swiss P AP from RUAG and .357 DAG.
The VPAM scale is as follows:[2] The Technische Richtlinie (TR) Ballistische Schutzwesten is a regulation guide in Germany for body armor.
Producers have to meet the criteria of the TR, if they want to participate in open competitive bidding made by German agencies.
The TR specifies different Schutzklassen (SK), which translates to protection classes, which a body armor can have.
[3] The TR scale is as follows:[3] This armor would protect against three hits, fired from 5±0.5 meters, as well as point-blank shots, of: This armor would protect against three hits, fired from 5±0.5 meters in an angle of 25°, as well as 3 shots at point-blank, of: The German TR are generally comparable to the American NIJ, but the German TR usually tests more threat scenarios, as there are no point-blank shots as well as no police special rounds.
In contrast the NIJ tests for bigger calibers and higher man stopping power.
[4] The Home Office Scientific Development Branch is governing standards and testing protocols for police body armor.
In spite of the more difficult test threats, the 16 mm (0.63 in) back-face deformation limit remains unchanged.
This rated vests on the following scale against penetration and also blunt trauma protection (deformation):[7] It is no longer part of the standard.
It also provides at least single hit protection against the threats mentioned in [Types I, IIA, II, IIIA, and III].
Textile armor is tested for both penetration resistance by bullets and for the impact energy transmitted to the wearer.
[10] It is measured by shooting armor mounted in front of a backing material, typically oil-based modeling clay.
This concluded that water, long-term use, and temperature exposure significantly affect tensile strength and the ballistic performance of PBO or Zylon fiber.
This NIJ study on vests returned from the field demonstrated that environmental effects on Zylon resulted in ballistic failures under standard test conditions.
[15] The NIJ's stab resistance standards (Standard–0115.00) define three levels of protection: For all three levels, the maximum blade or spike penetration allowed is 7 mm (0.28 in), with this limit being determined through research indicating that internal injuries to organs would be extremely unlikely at this depth of penetration.
The overtest condition, which is intended to ensure an adequate margin of safety in the armor design, permits a maximum blade or spike penetration of 20 mm (0.79 in).
[16] Although the US military requirements for body armor mirror the NIJ's on a surface level, the two are very different systems.
[citation needed] The Chinese Ministry of Public Security has maintained GA141, a standard document for describing the ballistic resistance of police armor, since 1996.
The standard defines the following grades using domestic weapons:[29]: 4 Levels higher than 6 are marked "special".
[29]: 11 Measuring the ballistic performance of armor is based on determining the kinetic energy of a bullet at impact (Ek = 1⁄2 mv2).
Because the energy of a bullet is a key factor in its penetrating capacity, velocity is used as the primary independent variable in ballistic testing.
However, as a result of the simplicity of making v50 measurements, this method is more important for control of armor after certification.
[30] The large body of casualty data made clear that in a combat situation, fragments, not bullets, were the most important threat to soldiers.
The second part of "Casualty Reduction" strategy is a study of velocity distributions of fragments from munitions.
The random nature of fragmentation required the military vest specification to trade off mass vs. ballistic-benefit.
The majority of military and law enforcement standards have settled on an oil/clay mixture for the backing material, known as Roma Plastilena.
The oil/clay mixture of "Roma" is roughly twice the density of human tissue and therefore does not match its specific gravity, however "Roma" is a plastic material that will not recover its shape elastically, which is important for accurately measuring potential trauma through back side signature.
The selection of test backing is significant because in flexible armor, the body tissue of a wearer plays an integral part in absorbing the high energy impact of ballistic and stab events.
This complexity requires very elaborate bio-morphic backing material systems for accurate ballistic and stab armor testing.
The use of harder Roma materials in the ISO draft norm makes this the most rigorous of the stab standards in use today.
