Mag-slip

The windings of the transmitter of the right- hand mag-slip, as drawn, are connected in parallel to the stator windings of the mag-slip in the left-hand follower unit, which must be of the follow-through transmitter type.

Source: wiktionary

The clay, as it is extruded from the die, passes over a roller attached to the spindle of a mag-slip transmitter (not shown), coupled electrically to a mag-slip receiver (Q), which rotates in unison with and at the same speed as the transmitter driven only by the clay column.

Source: wiktionary

Rotation of the control wheels actuates the total range display counters on the face of the control unit, and the mag-slip transmitters which control the track plotter actuators.

Source: wiktionary