Abstract: A circuit arrangement for processing signals occurring at randomly varying intervals wherein the processing time is not negligible. A portion of the signal path is divided into a plurality of identical parallel part-signal-paths, each having an electronic switch (16-19) controlled by a control circuit (29) in such a way that the electronic switch in a free part-signal-path is made conducting when a signal occurs during the processing time of the preceding signal. Correct processing of a greater number of signals is thus achieved than has been possible with known circuit arrangements.

Abstract: When mapping out the internal cross-sectional dimensions of elongated, tubular bodies, correlated values of the external cross-sectional dimensions and wall thicknesses are measured along measuring lines from the outside of the body and the sum of the wall thicknesses measured along each measuring line is subtracted from the external cross-sectional dimension measured along the same or substantially the same measuring line. This avoids the use of measuring means in the interior of the tubular bodies, whereby the measuring can be carried out much faster and without the danger of injuring the internal surface of the bodies.