Measuring distance from sensor to electrically conducting target by measuring simultaneously or sequentially impedances of two coils on a common magnetic core

摘要

Inductive sensor comprises a magnetic core (1) which has two coils (2,3) spaced by a distance (d0). To find the distance from the sensor to an electrically conducting target an alternating current is passed through them either simultaneously or successively and the difference between their impedances is found. The impedance difference is used to find the target distance after conventional calibration