Abstract: A ferrous article proximity sensor package includes a dual Hall element IC chip mounted at the end of a magnet. The axis of the chip, defined as being orthogonal to the chip face and equidistant the two Hall elements, is coaxial with the outer wells of the package but spaced away from the axis of the magnet. That exact position is such that the resulting difference in magnetic field strength at the two Hall elements is just enough to compensate for all the other factors that lead to an unwanted offset voltage in the sensor output. This package is made of two mating parts, one containing the magnet being eccentric with respect to the chip axis and the other containing the chip just above one magnet pole end. To achieve the abovedescribed desired offset condition in manufacturing, the one package part is simply rotated with the magnet relative to and within the other package part until the desired condition is met, and the two parts fastened together in that position.