1. Basic Plane―a plane through the centers of the right and left external ear openings and the lower edge of the eye sockets (§1131.B.Figure 1) of a reference headform (§1131.C.Figure 2) or test headform.
2. Helmet Positioning Index―the distance in inches, as specified by the manufacturer, from the lowest point of the brow opening at the lateral midpoint of the helmet to the basic plane of a reference headform, when the helmet is firmly and properly positioned on the reference headform.
3. Mid-Sagittal Plane―a longitudinal plane through the apex of a reference headform or test headform that is perpendicular to the basic plane (§1131.D.Figure 3).
4. Reference Headform―a measuring device contoured to the dimensions of one of the three headforms described in §1131.F.-M. (Table 2 and Figures 5 through 8) with surface markings indicating the locations of the basic, mid-sagittal, and reference planes, and the centers of the external ear openings.
5. Reference Plane―a plane above and parallel to the basic plane on a reference headform or test headform (§1131.C.Figure 2) at the distance indicated in Table 2.
6. Retention System―the complete assembly by which the helmet is retained in position on the head during use.
7. Test Headform―a test device contoured to the dimensions of one of the three headforms described in §1131.F.-M (Table 2 and Figures 5 through 8) with surface markings indicating the locations of the basic, mid-sagittal, and reference planes.

Authority Note

AUTHORITY NOTE: Promulgated in accordance with R.S. 32:190.

Historical Note

HISTORICAL NOTE: Promulgated by the Department of Public Safety and Corrections, Office of State Police, LR 27:62 (January 2001).