Abstract: An apparatus designed for measuring the magnetic flux distribution along magnetizable members, specifically, magnetically latching reed capsules, which apparatus is characterized by an elongate thrust arm, in tubular form, which is mounted to reciprocate along a path provided by spaced support members and which has a drive connection with a motor at one end thereof so that a tubular portion at the opposite end which carries search coils with leads enabling connection to an oscilloscope for recording flux intensity, will telescope the magnetic members which are supported in a holder at that end of the path and which extend into a tubular portion of a bobbin member mounted at that end of the path, within which the search coil is reciprocated and on which an energizing coil may be wound with connection to a current source.