Lighting for high-accuracy machining and inspection

Requirements for very-high-accuracy machining and inspection operations demand close temperature control of machines and work pieces. In order that these temperatures may be controlled to plus or minus 0.05 deg F, it was necessary to restrict the amount of heat energy which could radiate from the area lighting fixtures. Field tests have demonstrated that a combination of supply and exhaust air ducts connected to the air conditioning system plus housings fitted with a dual lens system to filter the infrared radiation, reduced by 90%, the amount of heat energy transmitted by the lighting system with only about an 18% reduction in the illumination level. (auth)