作为灯丝的钨丝,经过高温后会有一部分被升华掉,由于灯管与外界空气接触使得升华的钨的气体又在管壁被冷却而重新凝华成固态钨,所以日光灯用久后就会变黑。我们知道日光灯的启动全靠灯头,灯头也是一盏灯最热的地方,灯丝在此处消耗最大,自然就会出现两端变黑的现象。 As the filament of tungsten, after high temperature will be part of the sublimation, due to contact with the air outside the tube so that the sublimation of the tungsten gas is again in the tube wall is cooled and re-sublimation of solid tungsten, so a long time with a fluorescent lamp will Black. We know that the start of fluorescent lamp depends entirely on the lamp, the lamp is also the hottest place of a lamp, the filament consumes the most here, naturally there will be two ends of the black phenomenon.