HG/T 2257-2011Photographic chemicals - Determination of volatile matter in color couplers (English PDF)

1 Scope

This standard specifies the coupler in photographic chemicals Determination of volatile matter.

This standard applies to photographic chemicals volatile coupler in the determination of other chemicals in the security conditions allow determination of the present method may be used under the volatile content.

Foreword

This document was issued on 20 December 2011 by the Ministry of Industry and Information Technology of the People's Republic of China, and has been in force since 1 July 2012.

It replaces HG/T 2257-1991.

The document is under the responsibility of the Ministry of Industry and Information Technology.

About this edition

HG/T 2257-2011 is the current edition. It was issued on 20 December 2011 and has been in force since 1 July 2012, replacing HG/T 2257-1991.

HG/T 2257-1991 has been superseded: a specification that still cites it is citing a withdrawn edition.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 announced by the Ministry of Industry and Information Technology of the People's Republic of China.

Edition history and citation

HG/T 2257-2011 replaces HG/T 2257-1991. A specification, drawing or test report that cites the older number is pointing at a document that is no longer the one in force, and the two editions can differ in requirements, in test methods or in scope.

Where an edition is replaced, the Chinese standardization system keeps the number and changes the year: the number identifies the subject, the year identifies the text. That is why a citation without a year is ambiguous and a citation with one is not.

Classification and status

HG/T 2257-2011 carries no ICS number in the official record.

The HG/T prefix marks a recommended standard of China's chemical industry, issued by the Ministry of Industry and Information Technology. 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.

The document is under the responsibility of the Ministry of Industry and Information Technology, which is the body that maintains it and that will answer a formal question about its interpretation.

How this standard is designated

The full designation is HG/T 2257-2011. A citation should carry the number with its year, because the year identifies the text that applies.