Ballistic helmets testing

There are some cormnon misconceptions regarding combat helmet testing. One common misconception concerns the existence of National Institute of Justice (NIJ)-certified Level IDA helmets. The Nil Standard for Ballistic Helmets 0106.1 only certifies up to Level II for ballistic-type helmets. The only comprehensive Level IIIA testing protocol for helmets in the LIS is the H. P. White Helmet Test Procedure (HPW-TP-0401.01B). Additionally, the NIJ Standard does not provide arty information on how to measure blunt trauma deformation a standard operatingprocedure to assess trauma-related injury to the wearer. Testing protocols of NIJ Standard 0106.01 are employed by many manufacturers for testing helmets up to Level IDA (Nielsen, 2008 Scheetz et al., 1973). 

Another standard test for ballistic helmet is water immersion testing (MIL-H-4409A- Para 4.5.1). Normally the helmet is immersed in tap water at 16 to H°C for a minimum of 16 hours. At the end of this time, the helmet is removed and allowed to air dry for 12 hours minimum, or force air dried for six hours minimum under the same temperature conditions. The coating on the outside surface of the helmet is then examined for any evidence of softening, blistering or peeling. 

Helmets made in this way are tested in laboratories approved by the Ministry of Defence, the bonds being required to withstand exposure to extreme heat and cold, ballistic and drop tests—so simulating the rigours experienced in the field. 

Halkon, B., Velani, N., Harland, A., 2013. The development of a test methodology for the determination of cricket batting helmet performance when subjected to ballistic impacts, https // dspace.lboro.ac.uk/dspace-jspui/handle/2134/14051(accessed 21.10.14.). 

A typical helmet is expected to be between 5 and 10 mm thick, dependent on both material type and applicatioa The shell thickness is normally determined experimentally by the penetration test. The shell canbe made of either an injection-moulded thermoplastic or a pressure-moulded resin system, reinforced with ballistic resistance fabrics/fibres (Mills, 1996). Energy is absorbed when the helmet is impacted, with the shell bending and deformation of the underlying foam. The amount of the impact energy absorbed by the foam depends on ... 

Level IDA testing to NIJ Standard 0108.01 for ballistic material is only for testing flat armom- panels, which differ significantly from helmet curvature contours. NIJ Standard 0108.01 for ballistic material specifically excludes helmets... 

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