How to verify the installation and to test the low beam headlights?

  • Dec 26, 2019

The efficiency of the dipped headlights is significantly reduced by their wrong adjustment. With sufficient brightness of lights, road sections which are important for safe driving, are poorly lighted.

The displacement of the luminous flux toward the oncoming traffic lane in the opposite direction causes blinding of drivers of vehicles. It is necessary to periodically monitor the accuracy of the headlamps, which is a snap.

Requirements for the low beam headlights

Dipped beam is activated when driving at night on the lighted parts of the road, in the presence of oncoming traffic - on the dark road, as well as in tunnels. Luminous flux is directed in such a way that the road is illuminated in the driver's field of view from the front car and the distance to a distance of 60-70 m. The flow is shifted somewhat to the right, which provides improved lighting edge road.

The lens of lamp has transparent edges that act as lenses, distributing the brightness of the light spot and forming its shape.

Headlights for different vehicles are located at different heights from the ground. To ensure coverage not more predetermined road section, the automaker specifies decrease of the light beam axis, expressed as a percentage.

The value is applied to the body near the headlights. For car headlights which are located not greater than 0.8 m, this value is typically equal to 1%. This means that at a distance of 10 m upper limit of the luminous flux is reduced to 0.1 m.

Simplified testing methods

The car in the performance testing should be routine equipment. In the trunk should not be superfluous goods, and in the cabin - passengers. Headlight adjustment knob set to the neutral position. The works carried out in twilight or darkness.

You must select a horizontal platform located in front of a light wall, fence. The tool is required:

  • roulette;
  • plummet;
  • piece of chalk.
Fig. 1. Simplified testing methods
Fig. 1. Simplified testing methods

Fit the car against the wall and mark the middle between the centers of the headlights (fig. 1). Conduct by a plumb and chalk vertical line - 0. Mark on the wall the centers of headlights - CL and the CPU to push through their horizontal line - 3.

To drive away the car in reverse 5m Measure the height from the road to the center lights -. H. Calculate the flux reduction - h. For 1% decrease coefficient h is 5 cm. Draw a line 4 below the line 3 by an amount h. Mark the point and 0n 0n.

Turn on the dipped beam. Alternately dense material covering one of the lights, make sure that:

  • upper limit of the light spot coincides with the line 4;
  • triangles located above the line 4 are shifted to the right, their acute angle begins at points and 0n 0n.

When obvious deviations need to make the adjustments yourself or contact the service station. Specialists make adjustments more accurately, with the use of special optical instruments.