An automated measuring unit for measuring work surface luminous intensity has been developed and produced. The research of luminance level on a horizontal surface from a positional light fixture with parabolic concentrator after its incandescent light bulb change for more power-efficient ones (compact fluorescent and light-emitting diode lamps) has been conducted. Hereat, a decrease in luminous intensity by 20-55% has been observed. Light intensity distribution curves of the fixture with power-efficiency lamps have been measured and analyzed. It has been proved that in case of a large luminous element, the luminous flux distribution in space does not match the demands to fixtures with parabolic concentrator due to the fact that a part of luminous flux is dispersed in the space and does not arrive onto the work surface. Two conclusions have been made regarding the influence of this change on light intensity distribution curves of the fixtures and work surface luminous intensity.

Разработана и изготовлена автоматизированная измерительная установка для измерения освещенности на рабочей поверхности. Проведены экспериментальные исследования светотехнических характеристик световых приборов местного освещения с параболическим концентратором после замены в них ламп накаливания на более энергоэффективные. Сделаны выводы о влиянии такой замены на кривые силы света и освещенность на рабочей поверхности.