Description and Specification for Lab Tenders
Helmet Retention Tester.
Helmet Retention Tester is apparatus for dynamic test of retention system and retention test.
The retention system of helmets is subjected to a specified dynamic loading to determine its dynamic displacement, residual displacement, and damage to the retention system in order to assess the suitability of the helmet. It is further subjected to a dynamic loading at a tangential line on the rear part of the shell. After the test the inclination of helmet on the head-form is checked for suitability of its retention system. The Apparatus for Dynamic Test of Retention System and Retention Test of helmets consists of a rigid fabricated steel frame fitted with arrangements to carry out either of the two tests. The arrangement for dynamic test of retention system consists of a stand to hold the helmet by its shell from a hook connected to a screw to raise or lower it. The helmet is mounted over a head-form with initial loading device cum guiding system. A mass of specified weight is allowed to fall on the anvil of the loading device from a specified height. The mass is lifted with the help of a handle and chain arrangement and is held by a catch at the specified height. For dropping the mass, the catch is released and mass drops guided on a rod. The displacement of retention system is measured on a vertical scale.