Superseded Standard

ANSI/IEEE 455-1976

IEEE Standard Test Procedure for Measuring Longitudinal Balance of Telephone Equipment Operating in the Voice Band

Telephone companies and equipment manufacturers have generally agreed on a definition for longitudinal balance for many years. This agreement extends also to the basic approach followed when measuring balance. Testing a device for balance involves the application of a longitudinal voltage. Then any resulting metallic voltage is measured, and the ratio of the two voltages is used to develop a balance number. Unfortunately, agreement has ended at about this point. A number of different test circuits are used by different segments of the telephone industry. Although all of the existing test circuits have some merits supporting their use, the mere existence of varied circuits leads to differences in test results. In addition to differences related to the test set, test conditions and procedures can also affect the result. When an item of equipment is to be tested, there is often a test set or procedure,or both, capable of giving any desired result. Agreement on one way of testing for longitudinal balance has been sought. This standard represents such agreement. It defines the basic requirements of a standard test circuit. Reasonable tolerances are included so that a test-set designer will find considerable latitude to make the set his own way. Besides defining the requirements for a test circuit, this standard includes test conditions and procedures that must be established and followed. As a result, all test sets designed and used in accordance with the standard will produce the same balance number for a given test specimen. Similarly, comparing balance numbers for different devices will become more meaningful when all come from tests meeting the standard.

Superseded Standard
Superseded by
Board Approval
ANSI Approved:

Working Group Details

Other Activities From This Working Group

Current projects that have been authorized by the IEEE SA Standards Board to develop a standard.

No Active Projects

Standards approved by the IEEE SA Standards Board that are within the 10-year lifecycle.

No Active Standards

These standards have been replaced with a revised version of the standard, or by a compilation of the original active standard and all its existing amendments, corrigenda, and errata.

No Superseded Standards

These standards have been removed from active status through a ballot where the standard is made inactive as a consensus decision of a balloting group.

No Inactive-Withdrawn Standards

These standards are removed from active status through an administrative process for standards that have not undergone a revision process within 10 years.

No Inactive-Reserved Standards
Subscribe to our Newsletter

Sign up for our monthly newsletter to learn about new developments, including resources, insights and more.