ELECTROMAGNETIC POSITION INDICATOR
J.N. Young · 1957
A device was needed to indicate the axial position of a rod which is sealed up inside of a pipec Since the rod is magnetic (nonpermanent) and the pipe may be made of non~nagnetic stainless steel~ an electromagnetic systen1 i s used.. Basically~ the position indicator consists of a coil which fits over the pipe and an impedance measuring device which may be located remotely.Impedance measuring devices, using a bridge circuit, were described in the June 1957 issue of NUCLEONICS in the article on the Magnetic.Jack.This type has the advantage of requiring a relatively small amount of wire on the coils and of using the full scale of the metero It has the disadvantage of being too sensitive to extraneous influences ..