Displacement gauge that combines vector signals

A displacement sensor or displacment gauge (3) for detecting misalignment measures the dislocation of a machine part, such as a post (12), by means of four magnetic coils (24N, etc.) deployed 90 DEG apart around the post and each energized by an oscillator (36N, etc.). A reference position of the machine part (12) relative to another component (6) of the machine is first established. Subsequent displacement is detected and excessive displacement is indicated if it exceeds a predetermined threshold magnitude. Signals from the four coils are processed combined in such a way that the magnitude of the radius of a displacement of the machine part (12) from the reference position is ascertained and provided irrespective of the direction of the displacement. The provided signal equals the greatest of the absolute values of (a) a north/south displacement signal, (b) and east/west displacement signal, and (c) one or more combination signals that are derived from the north/south and east/west absolute value signals, and that represent the displacement in various intermediate directions e.g., east by northeast.