论文部分内容阅读
一、米的定义长度单位米是国际单位制中重要的基本单位之一。至今,米的定义只作过二次正式定义,目前正在准备进行新的第三次定义。第一次米的定义是在1889年第一届国际计量大会上通过的:“一米是铂铱米尺两条刻线间的距离”。为了使上述定义更加确切,1927年第七届国际计量大会作了如下更准确的规定: “长度单位是米,规定为国际计量局保存的铂铱尺上所刻两条中间刻线的轴线在0°时的距离。这根铂铱尺已由第一届国际计量大会宣
I. Definition of meters Length units are one of the most important basic units in the international system of units. To date, the definition of M has only been formally defined twice and preparations are under way for the third new definition. The first definition of meter was adopted at the first International Conference on Metrology in 1889: “One meter is the distance between two lines on a platinum-iridium meter.” In order to make the above definition more precise, the 7th International Conference of Metrology in 1927 made the following more precise provisions: "The unit of length is meters, stipulating that the axis of the two middle marks engraved on the platinum iridium scale held by the International Bureau of Measurement 0 ° when the distance between the platinum Iridium ruler has been declared by the first session of the International Metrology Conference