Abstract: The sensor (20) is intended for the detection of random signals, suitable for correlative signal processing, originating from a process in motion relative to the sensor, for example a flow passing through a pipeline (1). Signals of this nature are used, in particular, for the measurement of velocity or running time. The sensor (20) is subdivided into several sensor segments (21, 22, 23, 24) in order to increase sensitivity for a given spatial frequency filter effect. In the case of a capacitive sensor, each sensor segment consists of two electrodes encompassing the pipeline (1). The sensor segments (21, 22, 23, 24) are arranged along the direction of motion according to a coding selected on the basis of the desired spatial frequency filter effect, with the introduction of gaps (25, 25, 27) which are insensitive to the characterizing parameter of the process in motion.

Abstract: For the continuous contactless measurement of the shrinkage of textiles during the production process, the image of a portion of the textile surface is picked up both before and after the shrinkage and converted to analog electrical image signals by means of an image/signal transducer. The analog image signals are digitized by analog-digital converters and stored in image signal memories. A calculating unit determines from the stored digital image signals the periods of the textile structure both before and after the shrinkage in at least one evaluation direction, preferably in the longitudinal direction and in the transverse direction of the textile web. The change of length of the textile material in each evaluation direction is calculated from the ratio of the two periods determined in this direction. The method is in particular suitable for the measurement of the two-dimensional shrinkage of knitted textiles during the manufacturing process.

Abstract: Disclosed is a method and apparatus for correlating first and second signals where sampling values of the signals are multiplied together and discrete values of the correlation function are determined. In one embodiment, the signals are sampled at different sampling frequencies such that one sampling frequency is a multiple of the other sampling frequency. A number of the respective last sampling values of the more fully sampled signal are stored and each sampling value of the more rapidly sampled signal is multiplied simultaneously by all of the stored sampling values of the more slowly sampled signal. The results of the multiplication are separately summed corresponding to equal time displacements between the multiplied sampling values. In a further preferred embodiment, a microcomputer is programmed for sampling the two signals with sampling frequencies having a ratio 1:k. The more slowly sampled signals are stored in an n stage register.