Mẫu chuẩn thành phần kim loại SRM 1258-I
ertified Values for SRM 1258-I
Elements Mass Fraction
(%)
Expanded Uncertainty
(%)
Coverage Factor
k
Silicon (Si) 0.80 0.04 2.4
Iron (Fe) 0.080 0.003 2.6
Copper (Cu) 0.848 0.010 2.4
Manganese (Mn) 0.481 0.010 2.1
Magnesium (Mg) 1.00 0.03 2.3
Zinc (Zn) 1.03 0.02 2.4
Expiration of Certification: The certification of SRM 1258-I is valid indefinitely, within the measurement
uncertainties specified, provided the SRM is handled and stored in accordance with the instructions given in this
certificate (see “Instructions for Storage, Handling and Use”). Periodic recalibration or recertification of this SRM is
not required. The certification is nullified if the SRM is damaged, contaminated or otherwise modified