Heavy-duty LVDT is a displacement transducer. It comprises 3 coils; a primary and two secondaries. The transfer of current between the primary and the secondaries of the LVDT displacement transducer is controlled by the position of a magnetic core called an armature. On position measurement LVDTs, the two-transducer secondaries are connected in opposition. At the center of the position measurement stroke, the two secondary voltages of the displacement transducer are equal but because they are connected in opposition the resulting output from the sensor is zero. As the LVDTs armature moves away from center, the result is an increase in one of the position sensor secondaries and a decrease in the other. This results in an output from the measurement sensor.