暗室工作是金相检验工作中的一个组成部分。通常金相照片的冲洗、添印,都在避光的室内操作。为了适应无暗房的时候也能开展金相检验工作中的暗室工作,以及改善暗室工作人员的条件,我们在史无前例的无产阶级文化大革命的推动下,遵照毛主席关于“我们是主张自力更生的。”“备战、备荒、为人民。”的教导,依靠电工、木工师傅的协作,制作了一个小暗箱,从此,金相照片的印制工作走出了暗室。小暗箱的构造,以暗室结构和暗房袋为依据,用10毫米厚木板制作一个750×420×400毫米有盖的长方形箱体,正面挖二个圆洞(ф185毫米),每个洞用2毫米铁皮制成的法兰(ф250毫米)和垫圈(ф195×185×3), 缩口的袖套(里外为黑布,中间是4～6层红布,ф185×L400)用木螺钉紧固,顶盖挖三个观察窗(ф130毫米),窗口镶上深红色玻璃(如冲洗胶片时过亮,可用布帘遮住)。箱内正中放小型印相机,右侧放小型长 Darkroom work is an integral part of metallographic testing. Usually the photo processing, printing, are in the dark operation of the interior. In order to adapt to the dark room when the darkroom work can also be carried out in the metallographic examination work, as well as to improve the conditions for darkroom staff, we are in the unprecedented proletarian cultural revolution, driven by Chairman Mao on “We are advocating self-reliance.” “” Prepare for the war, prepare for the shortage, for the people. "The teaching, relying on the cooperation of electrician, carpenter, produced a small dark box, from then on, metallographic photo printing work out of the dark room. Small dark box structure, based on the darkroom structure and darkroom bag, with a 10 mm thick board to make a 750 × 420 × 400 mm covered rectangular box, front dig two round holes (ф185 mm), each hole with 2 Flange (ф250 mm) made of metal sheet and washer (ф195 × 185 × 3), shrink sleeve (inside and outside of the black cloth, the middle is 4 to 6 layers of red cloth, ф185 × L400) with a wood screw tight Solid, the roof dug three observation windows (ф130 mm), the window inlaid with dark red glass (such as the film too bright when washed, covered with a curtain available). Small box put the middle of the camera, put the small right