ABSTRACT
This chapter shows how standard photometry and colorimetry may be applied to light-emitting diode (LED) lamps. It analyzes how they may be compared with corresponding features of incandescent and fluorescent lamps and examines the LED-specific measurements and characterization because they remain very important for ongoing improvement of the field. Spatial flux distribution (SFD) is expected to become a more important lighting parameter, at least from design and measurement perspectives, as LED lamps become more common in the market. In contrast to LED sources, incandescent and fluorescent lamps by nature have larger, curvaceous, and continuous emitter surfaces that produce more uniform luminous intensity and SFD over wider spatial regions. The illuminance datasets show that the LED sample is significantly better in terms of providing higher luminance over a broader area on the desk-top surface. Typical LED manufacturer specification sheets include color coordinates, Correlated color temperature, and Color rendering index information; some also include color purity or deviation data.
