The four reference materials, as Certified Reference Materials(CRMs), had been approved by State Bureau of Technical Suppervision in 1997. The serial numbers are GBW07295, GBW07296, GBW07315 and GBW07316 respectively.
英
美
- 這4個(gè)標準物質(zhì)已于1997年被國家技術(shù)監督局批準為國家一級標準物質(zhì)，序號分別為GBW07295，GBW07296，GBW07315和GBW0731。
