GB/T 3971.3-1983The test methods for the technical specifications of multi-frequency register signalling for telephone auto-matic switching network (English PDF)

3 Measurement of the multi-frequency signal sending level, the signal frequency leakage level, the harmonic distortion and the intermodulation distortion

4 Test of the technical indices of the multi-frequency receiver

5 Test of the multi-frequency compelled cycle

Foreword

This document was issued on 15 December 1983 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 1984.

It is the first edition of this standard.

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

Classification: CCS M 12.

About this edition

GB/T 3971.3-1983 is the first edition of this standard. It was issued on 15 December 1983 and has been in force since 1 October 1984.

There is no earlier edition to compare it with, so a specification that has to refer to this subject can only cite GB/T 3971.3-1983 itself.

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.

Edition history and citation

GB/T 3971.3-1983 is a first edition: there is no earlier version of this standard, so a document that needs to refer to this subject can only cite GB/T 3971.3-1983 itself.

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

GB/T 3971.3-1983 carries no ICS number in the official record.

Its Chinese Standard Classification code is CCS M 12. 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.

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 GB/T 3971.3-1983. A citation should carry the number with its year, because the year identifies the text that applies.

In a catalogue or a filing system it is found under CCS M 12, the Chinese classification scheme by which a standard on this subject is filed and searched.