U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
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This report is an archived publication and may contain dated technical, contact, and link information |
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Publication Number: FHWA-HRT-04-137
Date: December 2005 |
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Enhanced Night Visibility Series, Volume VI: Phase II—Study 4: Visual Performance During Nighttime Driving in FogPDF Version (1.27 MB)
PDF files can be viewed with the Acrobat® Reader® APPENDIX K—AIMING PROTOCOLPROTOCOL SUMMARYVehicle/Headlamp Combinations Acronym List:
Setting up the Non-UV–A headlampsApplies to the following Vehicle/Headlamp combinations:
Finding the Hotspot: Align the VES so that the “hotspot” is located within the circle located on the aiming board. The headlamps have both gross and fine adjustments. Typically, only fine adjustments will be required if the headlights are not switched; gross will be required if the headlights are switched. Using the Photometer: To determine if the hotspot is in the correct location, you will need to use the International Light, Inc., IL1400A Radiometer/Photometer to measure the area of greatest intensity. There are two sensors for the photometer; the sensor for the visible light is marked with a “REG” label, and the sensor for the UV light is marked with a “UV–A” label. Use the sensor marked “REG.” Zero the Photometer: Remember to “ZERO” the photometer prior to checking each measurement. To do this, make sure that all headlamps are turned off. Remove the cap from the photometric sensor. Place the sensor at the alignment location for the headlamp to be aligned. Press the “ZERO” button; this will allow the photometer to measure any undesired background light and remove its effects from the actual light source value. The photometer is ready when the “ZEROING” message has changed back to the “SIGNAL” message. Turn the headlamp on and begin alignment. Isolating the Hotspot: Once you find the area you believe has the highest intensity, readings need to be taken in all directions around that location to ensure that is the hotspot. If the hotspot is in the correct location, the light is aligned and you can align the other light(s). Note that for non-UV lights, the HLBs in particular, the hotspots actually span a large horizontal swath, 2-4 inches wide. It is relatively easy to determine the hotspot vertically, but determining the hotspot horizontally requires more effort and patience given that the horizontal hotspot can be 2-4 inches wide. Special Instructions for HID alignment in the Blue Box: Remember that the HIDs require alignment with the photometer for rightmost (no. 2) headlamp and visual alignment based of the left (no. 1) headlamp based on the aligned right headlamp. This is noted on the alignment form.
Setting up the UV–A headlamps Applies to the following Vehicle/Headlamp combinations: SUV #2 Five UV–A (1-5) SUV #1 Hybrid UV–A (1&2)
Finding the Hotspot: Align the headlamps so that the “hotspot” is located on the crosshairs. The hybrid UV–A headlamps have fine adjustments. The five UV–A headlamps require shimming for the vertical location and wrench adjustments for the horizontal adjustment. Note that it is sufficient to line up the sensor on the crosshairs such that at least the edge of the sensor touches the center of the crosshairs. This means that there is a circular space around the center of the crosshairs, with a radius the size of the sensor in all directions (about 2 inches in diameter), in which the hotspot may be found. This is a larger margin of alignment error than allowed for the non-UV lights and is due to the nature of the mounting of the lights. Using the Photometer: To determine if the hotspot is in the correct location, you will need to use the International Light, Inc., IL1400A Radiometer/Photometer to measure the area of greatest intensity. There are two sensors for the photometer; the sensor for the visible light is marked with a “REG” label, and the sensor for the UV light is marked with a “UV–A” label. For UV–A light, use the photometer sensor marked “UV–A.” Zero the Photometer: Remember to “ZERO” the photometer prior to checking each measurement. To do this, make sure that all headlamps are turned off. Remove the cap from the photometric sensor. Place the sensor at the alignment location for the headlamp to be aligned. Press the “ZERO” button; this will allow the photometer to measure any undesired background light and remove its effects from the actual light source value. The photometer is ready when the “ZEROING” message has changed back to the “SIGNAL” message. Turn the headlamp on and begin alignment. Isolating the Hotspot: Once you find the area you believe has the highest intensity, readings need to be taken in all directions around that location to ensure that is the hotspot. If the hotspot is in the correct location, the headlamp is aligned and you can align the other light(s). Reference values for the Various Headlamps: Note: You look at this table as you look at the target board for calibration; it’s backwards when looking directly at the vehicles. HID
# 1 HLB & #2 HLB
Hybrid UV–A [#1]
Five UV–A [#2] Top Row lights
Five UV–A [#2] Bottom Row lights
Headlamp Alignment Form Date:______________________________ Inits:____________________________ HID
#1 HLB
#2 HLB
Hybrid UV–A [#1]
Five UV–A [#2] Top Row lights
Five UV–A [#2] Bottom Row lights
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