After the university's electrical department reviewed several fixture, lamp and ballast combinations, it selected Columbia Lighting's e-poc luminaire fitted with two T5 lamps and an EnergyMax tuned 1.04 ballast factor
* Keep ballast factor
(BF) high enough to provide proper level.
However, it is true that this process factors out the effect of the ballast factor
as the readings are typically normalized to the manufacturer's initial lumen rating of the lamps in a relative photometry report.
Issues such as losses due to heat build-up and ballast factor
, which further erode the relative photometry numbers, are ignored.
These methods include dimming, installation of ballasts or LED power supplies with a flexible range of ballast factors
, lumen maintenance controls, and settings for both highland low-end trim on the control system's output.
* Systems versus lamps, including variable ballast factors
with high-performance lamps