136
horizontal, with roughness height not more than 5 mm and deviation from the plane not more than
5 mm for 1 m. The measurements should be carried out in darkness (e.g. in a dark room).
The ambient temperature during measurements should be from 10 to 30 °
С
.
The truck prepared as mentioned above should be placed in such a way that its longitudi-
nal axis plane is perpendicular to the screen plane, and intersection line with the screen plane co-
incides with the central vertical line on the screen. The distance between the headlamp centers and
the screen should be 10 m.
Adjust the headlamps by-turn; non-adjustable headlamp should be covered with black
material.
Headlamps adjustment is carried out on fully equipped truck, i.e. the truck should have
the full fuel tank and all instruments and auxiliary equipment, accessories.
The wheels should be inflated to the pressure of the complete loading. The truck should
be placed for eight hours in the temperature stated above.
The headlamps adjustment means the setting of initial inclination angle of lower beam —
1.9 %.
After the headlamps are switched on the light beam indicates a light zone at the bottom
of the screen and a dark zone at the top of the screen, the line dividing light and dark zones is par-
allel to the line
А
-
А
on the left side of the screen and directed at 15° angle upwards from the in-
tersection point with vertical lines of headlamps centers on the right side of the screen.
Rotating the adjusting screws on the headlamp, remove the line dividing the light and the
dark zones so that it is 190 mm below the line A-A. Upon performing the above actions the truck
meets the requirements concerning the setting of the initial inclination angle of lower beam light.
The adjustment of the initial inclination angle of lower beam light can be performed with
the help of special devices designed for this purpose in accordance with their service manuals.
Such adjustment is controlled with the help of the screen. If necessary, methods of the headlamp
light adjustment by means of special devices should be corrected.
5.6.4.6 Mount and dismount the terminal blocks of actuators and control units with
the truck "ground" off only.
The bulbs of the headlamps should be replaced in the following order: turn out the headlamp
rubber rim bolts, turn out the optical element rim screws, remove the rim and optical element, re-
I-projection lines of headlamp
centers; II-site level; h=230 mm
Figure 109 - Marking of screen for
headlamps adjustment
