Test Standards
Bullet-resistant materials are usually tested by using a gun to fire a projectile from a set distance into the material in a set pattern. Levels of protection are based on the ability of the target to stop a specific type of projectile traveling at a specific speed. Experiments suggest that polycarbonate fails at lower velocities with regular shaped projectiles compared to irregular ones (like fragments), so that testing with regular shaped projectiles probably gives a conservative estimate of its resistance. When projectiles do not penetrate, the depth of the dent left by the impact can be measured and related to the projectile’s velocity and thickness of the material. Some researchers have developed mathematical models based on results of this kind of testing to help them design bulletproof glass to resist specific anticipated threats.
Well known standards for categorizing ballistic resistance include the following:
- Summary of Euronational (EN) 1063 test conditions in English
- Summary of Underwriter’s Laboratory (UL) ballistic resistance test conditions in English
- U.S. Department of Defense specifications for purchase of transparent armor – includes standards for bullet resistance (ATPD 2352P).
- U.S. National Insititute of Justice (NIJ) standard for ballistic resistant protective materials (NIJ Standard 0108.01).
Read more about this topic: Bulletproof Glass
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