4.SETTING UP THE DEVICE
The device shall be set up as follows:
the device shall be positioned on the seat;
it shall then be loaded with a force of 550 N at a point 50 mm in front of joint (A), and the two backrest boards shall be lightly pressed tangentially against the backrest;
if it is not possible to determine a definite tangent to the lower area of the backrest, the lower backrest board in vertical position must be lightly pressed against the backrest;
in the case of seats with a suspension adjustable to the driver’s weight, the suspension shall be set so that the seat is at a point equidistant from its two extreme positions.