Abstract: A digital displacement transducer to provide a digital output linear related to the displacement of a reference surface of an object. An eight track tape unit is coded with information related to displacements of 1/256 of an inch and applied to the reference surface. Means are then provided to assume the coded information of the tape unit; the means are of lesser coercivity than the tape unit. The information means is pulsed so that the information contained is the same, and a read out head is provided to read out which information was shifted, and thereby indicate the position of the reference surface of the object. A method is also provided to encode the information in the information means, switch the information therein, and obtain a read out.

Abstract: Magnetic cores of clamp-on type current measuring devices having a Hall-effect device for measurement of D.C. currents are provided with stabilizing coils which are periodically energized to substantially eliminate the characteristic hysteresis effect of the core material. A magnetic core of the type which is split to permit opening and subsequent clamping onto a conductor, has one section thereof provided with an air gap in which the Hall-effect device is positioned. A stabilizing coil is positioned on one section of the magnetic core and the coil and is periodically energized with a damped oscillatory current. This damped oscillatory current is at least applied immediately prior to the taking of any current measurement and is preferably applied periodically to maintain the stability of the magnetic core.