Abstract: A method for measuring the attenuation in digital transmission lines between a switching center and a subscriber station, with a first pulse of a known frequency spectrum being sent from the switching center to the transmission line. From the multitude of the reflections received by the switching center in the time domain that pulse is selected which was caused by the total reflection at the end of the line of a certain subscriber station. The frequency spectrum of the selected pulse is determined and from the frequency spectra of the outgoing pulse and the selected received pulse, the attenuation of the transmission line is determined, depending on its frequency. To achieve the extremely high dynamics necessary for this and to obtain a pulse which is free of any overshoot, reflection measuring is carried out selectively in the frequency range and the pulse is calculated per Fourier transformation.

Abstract: A method for data or measured value averaging and compression for measuring instruments, particularly for spectral analyzers, in which in successive measuring runs with respect to measuring intervals minimum and maximum values and their precise position are determined and used for averaging taking account of the values determined at the same locations during further measuring runs. By means of a measured value or data determination dependent on the position of the fixed minimum and maximum values, it is ensured that an effective noise averaging and a reliable detection of narrow pulses are made possible.