Social work practice : a Canadian perspective

An encapsulated magnetic tachometer pickup for insertion in an aperture of a fuel or oil pump housing for detecting the rotational speed of a gear in the pump which is driven in proportion to engine RPM includes a pole piece adapter substantially perpendicular to and radially extending from the axis of the pole piece and connected thereto. The adapter is positioned to have the teeth of the pump gear move transversely across its sensing portion when the gear rotates. A magnet connected to the pole piece causes a magnetic field to be generated in the pole piece and pole piece adapter which changes as the result of the rotation of the gear across the sensing portion of the pole piece adapter. The changing flux induces a current in a coil mounted on the pole piece which in turn is connected to a signal translating network for indicating engine RPM.