Headlamp Aiming Location and Equipment

All equipment for testing headlamps must comply with the SAE Recommended Practice for Headlamp Inspection Equipment.

If a headlamp testing machine is used, it should give results equivalent to those obtained using the screen procedure. It should be in good condition and properly adjusted, and should be used in accordance with the manufacturer's instructions. Machines using a photoelectric cell or cells to determine aim, should also include a visual screen upon which the beam pattern can be projected proportional to its appearance and aim on a screen at 7.62 m (25 feet). The screen should be plainly visible to the technician who is adjusting the headlamps, and should have horizontal and vertical reference lines to permit visual appraisal of the headlamp beam.

The area should be darkened and large enough to allow for the vehicle and an additional 7.62 m (25 feet) measured from the face of the headlamps to the front of the screen. The floor on which the vehicle rests must be parallel with the bottom of the screen. If the floor is not level, compensate accordingly.

It a screen is used, it should be at least 1.52 m (5 feet) high by 3.66 m (12 feet) wide with a matte white surface well shaded from extraneous light, and properly adjusted to the floor on which the vehicle stands. The screen should be moveable so it can be aligned parallel with the rear axle of the vehicle. It should be positioned so that a horizontal line drawn perpendicular to the centerline of the screen will pass an equal distance midway between the two headlamps.

The screen should be provided with a vertical centerline, two laterally adjustable vertical tapes, and one vertically adjustable horizontal tape.

If a regular commercial aiming screen is not available, the screen may consist of a wall having a clear uninterrupted area at least 1.83 m (6 feet) high by 3.66 m (12 feet) wide. The surface should be finished with a washable no-gloss white paint.

After the aiming screen has been set up and located, paint or tape a reference line on the floor 7.62 m (25 feet) from the screen. The vehicle should be parked with the front of the headlamps directly over this reference line.