scope:

General

This specification provides the outline requirements for an instrument to be used for counting phase and amplitude hits on telephone-type circuits. The instrument will independently count the number of phase hits and the number of amplitude hits that occur in a given period of time.

Phase or amplitude hits are defined as sudden positive or negative changes in phase or amplitude of an observed test signal which exceed a specified threshold and persist for a period of time greater than a specified duration.

The specifications given below for the transmitter and receiver input section shall correspond with §§ 2.2 b) to 2.2 d) and §§ 2.3 b) to 2.3 d) of Recommendation O.91 in order to facilitate the combination of this instrument with a phase jitter meter conforming to Recommendation O.91 in one set.