Vehicles have been equipped with asymmetric light distribution headlights (headlamps) since they appeared on the market in 1957. Headlights (headlamps) were first aimed at the so-called “10-metre wall” or “25 feet wall” or even “adjustment screen”. That means a vehicle is driven to a distance of 10m (25 feet) in front of a white wall, which has certain markings on it according to regulations. The headlights (headlamps) are then checked or adjusted on the basis of these markings. This has remained the testing method until today and is still used particularly for checking agricultural or specialist vehicles, and also in quality control departments in vehicle assembly plants. One of the disadvantages of this method is that you need a relatively, large, white and free wall, and a corresponding amount of space to go with it and also is considered a very subjective method as it depends on the operators opinion. Neither of these were, or are, exactly easy to find in a garage.
As already mentioned, this method is still mainly used today for vehicles where the upper edge of the headlights is higher than 140 cm above the ground. The vehicle is driven on to a level surface, to a distance of 10 metres from a vertical, white wall. The process to follow to perform a manual aiming or adjustment of headlights (headlamps) is as follows:
The following lines have to be marked on the wall:
Line A: Extend the longitudinal axis of the vehicle to the test wall and mark it with a vertical line. | Line B and C: Measure the distance X of the vehicle headlight (center of the light bulb to center of the light bulb) and mark it on the wall symmetrically to Line A. | Line D: Draw this line at a distance “e” below Line H: e=H/3 cm. | Linea H: Measure the height of the center of the headlights (headlamps) above the ground draw the line on the test wall parallel to the ground. After all the markings have been done:
Cover the right headlight and align the left headlight so that the horizontal part of the cutoff line touches Line D. Then align the headlight laterally. The bend between the horizontal and the sloping (asymmetrical) part of the cut-off line must lie on Line B. Then align the right headlight in the same way. In this case, the bend of the cut-off line lies on Line C.
SEETECH can provide to your company best in class solutions including:
- Leveled platform with centering.
- 5m wide wall with special non-reflectan paint.
- Audit tools such: auto leveling laser.