Non-Intrusive Testing Using Programme Statistics

Statistical distribution curves are introduced as a means for monitoring the performance of sound broadcast circuits in situations where removal of circuits from service requires an interruption in transmission. Gradual drift of circuit parameters can be monitored in addition to performance tests on circuits or equipment under operational conditions. The Spectral Amplitude Distribution (SAD) can be used to characterise non-linear equipment like limiters or compressors or any other equipment in the transmission circuit. The Time Amplitude Distribution (TAD) is not a sensitive indicator of changes in signal parameters. Quality of the broadcast programme is reflected in certain parameters of the distribution curves and these may be developed to give an objective measure of quality. The results of measurements on ´live´ broadcasts are presented.