Document ID: chunk:federal_register_of_legislation:F2023L01006:reg:780:p1
Version: federal_register_of_legislation:F2023L01006
Segment Type: reg
Provision Reference: reg 780 (pt 1/8)
Character Range: 78347–81204

780                                0.000 0  0.000 0      0.000 0
(*) Changed in 1966 (from 3 to 2)

Explanatory figure
Example of device for measuring the reflection factor of spherical mirrors

C = Receiver
D = Diaphragm
E = Window of entry
F = Window of measurement
L = Lens
M = Object window
S = Light source
(S) = Integrating sphere

Annex 7
Procedure for determining the radius of curvature "r" of the reflecting surface of a mirror
         1. Measurement
         1.1. Equipment
         A "spherometer" similar to the one described in Figure 1 of this annex having the indicated distances between the tracing pin of the dial gauge and the fixed legs of the bar is used.
         1.2. Measuring points
         1.2.1. The principal radii of curvature shall be measured at three points situated as close as possible to positions at one-third, one-half and two-thirds of the distance along the arc of the reflecting surface passing through the centre of this surface and parallel to segment b, or of the arc passing through the centre of the reflecting surface which is perpendicular to it if this arc is the longer.
         1.2.2. Where, owing to the size of the reflecting surface, it is impossible to obtain measurements in the directions defined in paragraph 2.1.2.2.2. of this Regulation, the Technical Services responsible for the tests may take measurements at the said point in two perpendicular directions as close as possible to those prescribed above.
         2. Calculation of the radius of curvature "r"
         "r" expressed in mm is calculated from the formula:
         Where:
         rp1 = the radius of curvature at the first measuring point,
         rp2 = the radius of curvature at the second measuring point,
         rp3 = the radius of curvature at the third measuring point.
Figure 1
Spherometer

Annex 8
Procedure for determining the "H" point and the actual torso angle for seating positions in motor vehicles[12]
              Appendix 1 - Description of the three dimensional "H" point machine (3-D H machine)1
              Appendix 2 - Three-dimensional reference system1
              Appendix 3 - Reference data concerning seating positions1

Annex 9
Test methods for close-proximity rear-view field of vision
         1. Field of vision
         The requirements of field of vision defined in paragraphs 15.2. of this Regulation can be tested under the conditions described in this Annex.
         1.1. Test objects
         Each test object shall be a right circular cylinder that is 0.8 m high and 0.3 m in external diameter. Each test object shall be marked as follows.
              (a) The test object shall have a painted patch measuring 0.15 m x 0.15 m that can be moved from the bottom to the top of the side of the cylinder.

              (b) The painted patch shall be of a colour that contrasts with