GB/T 223.21-1994Methods for chemical analysis of iron, steel and alloy--The 5-Cl-PADAB spectrophotometricmethod for the determination of cobalt content (English PDF)

3 Reagents

4 Analytical procedure

5 Calculation of the analytical results

6 Precision

Foreword

This document was issued on 17 January 1994 by the State Administration for Market Regulation and the Standardization Administration of the People's Republic of China, and has been in force since 1 October 1994.

It replaces GB 223.21-1982.

Classification: ICS 77.080, CCS H11.

About this edition

GB/T 223.21-1994 is the current edition. It was issued on 17 January 1994 and has been in force since 1 October 1994, replacing GB 223.21-1982.

GB 223.21-1982 has been superseded: a specification that still cites it is citing a withdrawn edition.

The interval between issue and effect is the transition period. It exists so that producers, laboratories and buyers can requalify products, revise procedures and use up documentation before the new text becomes the one that applies. The date on this page is the official one from the record of the Standardization Administration.

Classification and status

GB/T 223.21-1994 is classified under ICS 77.080, in the field of metallurgy. ICS is the International Classification for Standards, the same scheme used by ISO and by the national bodies of most countries, which is what allows a Chinese standard to be placed beside its foreign counterparts on subject rather than on number.

Its Chinese Standard Classification code is CCS H11. CCS is the domestic scheme, a letter for the sector and two digits for the subject within it, and it is the code by which the standard is filed and searched in China.

The GB/T prefix marks a recommended national standard. It is not, in itself, law: it becomes binding when a contract names it, when a regulation or a mandatory standard refers to it, or when a producer declares conformity with it. In practice that covers most of the cases in which it will be read — a purchase specification, an inspection agreement or a certification scheme.