ZERO-DISTANCE IN-PLACE INDOOR LUMINAIRE FLUX MEASUREMENTS

This paper describes an instrument that can measure relative luminaire flux outside the photometric laboratory. The measurement is taken wit h the instrument flush against an installed luminaire. Because a labor atory is not required for the measurements, the instrument should be u seful for studies that involve a relatively large luminaire sample set , such as the evaluation of luminaire dirt depreciation (LDD) over tim e. Among the issues to be discussed in this paper are: 1. neutralizati on of the effect of temperature; 2. maximizing the flux integration ef fect in the limited instrument cavity available; 3. re-reflected lumin aire flux and the associated theoretical error; and 4. a suggested res earch procedure for an LDD study. Data presented include comparisons o f flux measurements with the new instrument.