Lighting is a major element of operating costs for most facilities. Lighting costs involve both energy and maintenance. A company wasconsidering replacing its existing lighting system and wanted to determine the actual energy consumption of the different products it was considering. The could not be accomplished simply by examining manufacturer's specs because the specs were inconsistent, incomplete and based on different operating conditions. The plant engineers asked the lighting suppliers to submit sample units for evaluation. He measured the power consumption, power factor, displacement power factor and harmonic spectrum of each unit. Power consumption and displacement power factor translate directly to operating cost. High levels of harmonic distortion can cause problems for transformers, circuit breakers and other parts of the electrical distribution system. The plant engineer chose the Fluke 43B power quality analyzer http://us.fluke.com/usen/products/Fluke+43B.htm to make these measurements. He made comparisons of all the key electrical factors for four competing products on a level playing field. Details of the measurements can be found in this application note: http://tinyurl.com/lightapp . The measurements helped the plant engineer make a decision on lighting suppliers that will save hundreds of thousands of dollars over the life of the lighting system.