EFFECT OF BULB REPLACEMENT OF THE PHOTOMETRIC AIM OF ECE H4 TUNGSTEN HALOGEN HEADLAMPS

A study has been made of the effect of bulb replacement on the photometric aim of European (ECE) automobile headlamps and compared with similar work on North American (SAE) systems by the Highway Safety Research Institute of the University of Michigan. Measurements have been made at NAE of the orientation of the low beam pattern of a sample of 36 ECE H4 tungsten halogen bulbs representing 6 bulb groups. Mean values of photometric aim and corresponding values of standard deviation have been deduced and tests to assess the statistical significance of observed deviations have been applied. The result showed significantly smaller deviations in vertical aim and larger deviations in horizontal aim for ECE bulbs compared to SAE sealed beam units. Some significant differences were observed between ECE bulb groups but deviations for the overall sample were close to allowable limits specified in ECE and SAE documents and less than changes in vehicle attitude resulting from other factors. The results are discussed in terms of aiming procedures recommended following bulb replacement.

  • Corporate Authors:

    National Research Council of Canada

    NAE-DME Publications Section, Building M-16
    Ottawa, ONo K1A 0R6,   Canada 
  • Authors:
    • BROWN, R G
    • Charlesworth, A M
    • Pinkney, HFL
  • Publication Date: 1983-3

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00387419
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: LTR-ST-1450, HS-036 386
  • Files: HSL, TRIS, USDOT
  • Created Date: Aug 30 1984 12:00AM