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1千克究竟有多重?“国际千克原器”说了算!国际千克原器是一个高39毫米、底面直径也为39毫米的圆柱体,由铂铱合金制成,其中铂含量占90%,铱含量占10%。作为极其重要的质量基准,从1889年以来,它一直被保存在法国巴黎国际计量局。专家们用三层玻璃将它罩好,最外一层玻璃罩里还抽成半真空,以防空气和杂质进入。国际千克原器还有几十个复制品,存放在不同国家,作为国家基准。时光流逝,问题逐渐显现出来。2013年1月初,德国《计量学》杂志刊载研究报告称,表
International kg original is a high 39 mm, the bottom diameter of 39 mm cylindrical, made of platinum iridium alloy, platinum content of which 90 %, Iridium content of 10%. As a critically important quality benchmark, it has been kept at the International Bureau of Metrology in Paris, France, since 1889. Experts use three layers of glass to cover it, the outermost glass cover is also made into a semi-vacuum to prevent the entry of air and impurities. There are dozens of replicas of international kilograms, stored in different countries as a national benchmark. The passage of time, the problem is gradually revealed. In early January 2013, the German “Metrology” magazine published a study said the table