Pos Service Holland (SA) Pty Ltd. 

To test the core of the armature, you simply place it on the V-block, rest the supplied metal strip on the core and slowly turn the armature around its axis. Possible short circuits are identified by small vibrations of the metal strip. The faulty collectors are located where the armature slot and the metal strip meet.

Detecting possible short circuits between the commutator segments of the direct current armature can be done with the supplied test probs. Simply rest the two prods on two adjoining commutator segments and slowly turn the armature around its axis. The ammeter shows if there are any problems with the armature.