TIA ANSI/TIA-470.220-C

This standard defines the acoustic and electrical performance requirements of analog telephone alerters (sometimes referred to as ringers) connected to the Public Switched Telephone Network (PSTN).

This document proposes or references at least one measurement procedure for each technical requirement. However, these procedures are not exclusive. Any measurement procedure and equipment that can result in an identical measurement is considered valid.

While the procedures may call out specific test points within the requirements, the full range of the requirements take precedent over the test method.