LAMP LIFE PERFORMANCE OF HIGH PRESSURE SODIUM LAMPS IN THE CITY OF LONDON - REPORT NO 4

The city has been changing all lighting on main traffic routes and now has 1573 400 watts son/t lamps in use on 19 km of classified roads. This report describes the performance of 653 Phillips lamps some of which have been operating satisfactorily after some 30000 hours of use. The lamp life performance given in a schedule form shows that the failure rate for the first 550 lamps was 3.3 per cent before 6000 hours, 7 per cent before 8000 hours and 11.8 per cent before 10000 hours. Reliability has increased and there have been no failures in the last 215 lamps to be installed. Lamps made by other manufacturers have not proved so reliable with a failure rate of 49 per cent before 9000 hours compared with 9.3 per cent for the Phillips unit. The luminous efficiency of the 400 watt son/t lamp has improved by a third since 1966. Results included in the report show that the son/td linear high pressure sodium lamp was far less reliable. /TRRL/

  • Corporate Authors:

    Association of Public Lighting Engineers

    78 Buckingham Gate, Westminster
    London SW1E 6PF,   England 
  • Authors:
    • Austin, B R
  • Publication Date: 1976-9

Media Info

  • Features: References; Tables;
  • Pagination: p. 85-87
  • Serial:
    • Public Lighting
    • Volume: 174
    • Issue Number: 41
    • Publisher: Association of Public Lighting Engineers

Subject/Index Terms

Filing Info

  • Accession Number: 00149017
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analytic
  • Files: ITRD, TRIS
  • Created Date: Jun 17 1977 12:00AM