IEC CISPR 5
Radio interference measuring apparatus having detector other than quasi-peak
|Publication Date:||1 January 1967|
The original aim of the CISPR method of measurement for the frequency range 150 kHz to 1 605 kHz was to provide an objective assessment of interference which would be a measure of the extent of its effect on the reception of radio telephony. For the reasons set out in the introduction to CISPR Publication 1, Specification for CISPR Radio Interference Measuring Apparatus for the Frequency Range 0.15 MHz to 30 MHz, the method was retained for the frequency range 0.15 MHz to 30 MHz, while the introduction to CISPR Publication 2, MHz to 300 MHz, states the reasons for extending the use of the method for measurements in the frequency range 25 MHz to 300 MHz.
The information obtained with a quasi-peak instrument is limited. Many investigators have found a need for measuring instruments having indicators other than quasi-peak.
It seems appropriate, therefore, that the scope of CISPR specifications should be extended to include forms of indication other than quasi-peak. Instruments using the quasi-peak detector still remain as the basic reference for determining compliance with CISPR limits. From time to time, alternative methods of measurement utilizing the detectors described herein may be permitted. While the requirements for measuring apparatus to be used with the various types of detectors described herein are prescribed quite generally, the limitations imposed by the use of these with instruments as prescribed in CISPR Publications 1 and 2 are also clearly indicated.
This specification is divided into three parts, each dealing with a specific type of output meter.
Note that although in this specification the performance requirements of the various detectors are specified in terms of their responses to regularly repeated impulses, these detectors may be expected to find application for the measurement of types of interference other than impulsive. For example, the average and the r.m.s. detectors may be useful in measuring broadband interference having a quite random nature, as well as certain types of narrow-band interference.