痕迹量 meaning in English

minor value
trace amount
trace element

Sampling and analysis of iron , steel and other ferrous metals - methods of analysis - determination of lead - steel : spectrophotometric method for trace amounts
铁钢和其他铁金属的抽样和分析.分析方法.铅的测定.钢:痕迹量分光光度测定
Sampling and analysis of iron , steel and other ferrous metals - methods of analysis - determination of cobalt - steel , irons and steelmaking materials : spectrophotometric method for trace amounts
铁钢和其他铁金属的抽样和分析.分析方法.钴的测定.铁钢和制钢材料:痕迹量的分光光度测定