Helmet Impact Absorption Test for DOT & ECE

The ECE standard has the most stringent 'peak g' rating which on face value is the most re-assuring. However, while the other standards (SNELL and DOT) all employ a hemispherical anvil which increases the concentration of loading and challenges the shell to withstand puncturing, the ECE does not and the nearest equivalent is the kerbstone.

During the test, the helmet is fitted to a metal head (see picture) and dropped onto a steel anvil from a height of 287cm in order to get an impact speed of 27km/h. Four points on the helmet are each tested once and the anvils are both flat and rounded. Furthermore, the helmet is then dropped chinguard first onto a flat anvil from a height of 155cm. The velocity and duration of impact are both measured by sensors on the dummy head and when analysed, the acceleration of the head due to gravity must not exceed 275g.

The Head Injury Criteria (HIC) factor is a measurement of the total impact energy onto the head. It is usually calculated by multiplying the velocity with the duration of impact. The maximum permissible figure for this is 2,400. Reducing the total peak g and also the duration of impact will provide the rider with the best protection.

Chinstrap testing is also essential for helmets to get the necessary certificates.The chin strap is also tested by hanging a mass from it (a static load) and then dropping a proportion of this mass (a dynamic load) from a height of 75cm. This must not displace the chin strap by more than 35mm (from the dynamic load) and the static load must not displace the chin strap by more than 25mm.

If any question, please email me anytime.