ITU O.41:1994
ITU O.41:1994 Psophometer For Use On Telephone-type Circuits Defines the basic requirements for an instrument to measure noise and other interfering signals on telephone circuits.
Table of Contents
1Introduction2General
3Specificrequirements
3.1Inputimpedance
3.2Longitudinallosses
3.3Measuringrange
3.4Calibrationaccuracyat800Hz
3.5Relativegainversusfrequency(frequency
weighting)
3.6Detectorcircuitcharacteristics
3.7Detectoranddisplaydynamics(measurement
averagingtime)
3.8Linearity
3.9Outputindicator
3.10Operatingenvironment
AnnexAComparisonofITU-TandNorthAmericanweightings
AnnexBLevelandnoisemeasurementsatinterfaceswith
compleximpedances
B.1Levelmeasurementsatinterfaceswithreal
impedancefGeneralconsiderations
B.2Levelmeasurementsatinterfaceswithcomplex
impedances
B.3Conclusion
References