十亿分之一级 meaning in English
part-per-billion range
Examples
- Standard test method for determining residual vinyl chloride monomer content in ppb range in vinyl chloride homo - and co - polymers by headspace gas chromatography
用液上气相色谱法测定氯乙烯均聚物和共聚物中的十亿分之一级残余氯乙烯单体含量的标准试验方法