Two experiments have been carried out to compare high-pressure sodium (HPS) lighting with fluorescent high-pressure mercury (MBF/U) lighting which it often replaces in industry. The first compares results in two identical rooms, one lit by each source in turn, the other lit by a variable tungsten-halogen lamp. Results show that on average the subjects would prefer 23% more illuminance on the room surfaces from the HPS lamp than from the MBF/U. The second experiment investigated the perceived brightness of HPS and MBF/U lamps, using an intermediate tungsten halogen lamp. From this it was found that the subjects perceived the MBF/U light to be almost twice as bright as the HPS light.
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References
1.
Ferguson H.M. and Stevens W.R.Relative brightness of coloured light sourcesTrans. Illum. Eng. Soc. (London) 21(9) 227 (1956)
2.
Boyce P.R.Investigations of the subjective balance between illuminance and lamp colour propertiesLighting Res. Technol.9(1) 11- 24 (1977 )
3.
Aston S.M. and Bellchambers H.E.Illumination, colour rendering and visual clarityLighting Res. Technol.1(4) 259-261 (1969)
4.
Bellchambers H.E. and Godby A.C.Illumination, colour rendering and visual clarityLighting Res. Technol.4(2) 104-106 (1972)
5.
Berman S.M., Jewett D.L., Fein G., Saiha G. and Ashford F.Photopic luminance does not always predict perceived room brightnessLighting Res. Technol.22(1) 37-41 (1990)
6.
Light as a true visual quantity: principles of measurement CIE Publication 41 (Paris: Commission Internationale de l'Eclairage) (1978)
7.
Lynes J.A.Photometry or reality?Proc. CIBSE National Lighting Conf. (1992)
8.
Berman S.M.Tuning the light spectrum to improve energy efficiencyInternational Association for Energy-Efficient Lighting Newsletter2/92 (1992)
