Annex 1312). Then carefully return the back pan to the seat back. Care must be exercised throughout the remainder of the procedure to prevent the 3-D H machine from sliding forward. 3.11. Install the right and left buttock weights and then, alternately, the eight torso weights. Maintain the 3-D H machine level. 3.12. Tilt the back pan forward to release the tension on the seat back. Rock the 3- D H machine from side to side through 10° arc (5° to each side of the vertical centre plane) for three complete cycles. to release any accumulated friction between the 3-D H machine and the seat. 3.12.1. During the rocking action, the T bar of the 3-D H machine may tend to diverge from the specified horizontal and vertical alignment. The T bar must therefore be restrained by applying an appropriate lateral load during the rocking motions. Care is exercised in holding the T bar and rocking the 3-D H machine to ensure that no inadvertent exterior loads are applied in a vertical or fore and aft direction. 3.12.2. The feet of the 3-D H machine are not to be restrained or held during this step. If the feet change position, they should be allowed to remain in that attitude for the moment. 3.12.3. Carefully return the back pan to the seat back and check the two spirit levels for zero position. If any movement of the feet has occurred during the rocking operation of the 3-D H machine, they must be repositioned as follows: 3.12.4. Alternately, lift each foot off the floor the minimum necessary amount until no additional foot movement is obtained. During this lifting, the feet are to be free to rotate; and no forward or lateral loads are to be applied. When each foot is placed back in the down position, the heel is to be in contact with the structure designed for this. 3.12.5. Check the lateral spirit level for zero position; if necessary, apply a lateral load to the top of the back pan sufficient to level the 3-D H machine's seat pan on the seat. 3.13. Holding the T bar to prevent the 3-D H machine from sliding forward on the seat cushion, proceed as follows: 3.13.1. Return the back pan to the seat back; 3.13.2. Alternately apply and release a horizontal rearward load, not to exceed 25 N, to the back angle bar at a height approximately at the centre of the torso weights until the hip angle quadrant indicates that a stable position has been reached after load release. Care is exercised to ensure that no exterior downward or lateral loads are applied to the 3-D H machine. If another level adjustment of the 3-D H machine is necessary, rotate the back pan forward, re-level, and repeat the procedure from paragraph 3.12. of this Annex. 3.14. Take all measurements: 3.14.1. The coordinates of the "H" point are measured with respect to the three- dimensional reference system. 3.14.2. The actual torso angle is read at the back angle quadrant of the 3-D H machine with the probe in its fully rearward position. 3.15. If a re-run of the installation of the 3-D H machine is desired, the seat assembly should remain unloaded for a minimum period of 30 minutes prior to the rerun. The 3-D H machine should not be left loaded on the seat assembly longer than the time required to perform the test. 3.16. If the seats in the same row can be regarded as similar (bench seat, identical seats, etc.) only one "H" point and one "actual torso angle" is determined for each row of seats, the 3-D H machine described in Annex 1312 being seated in a place regarded as representative for the row. This place is: