A device for measuring the position of a first body relative to a second body comprising: a first body which further comprises an electrical intermediate device; a second body which further comprises at least two inductors energised with an alternating current and at least one of which is formed by a planar spiral winding on a printed circuit board normal to the measurement axis and attached to the second body; arranged such that displacement of the electrical intermediate device causes a change in inductance of the planar spiral winding and whereby measurement of the ratio of the inductances indicates the position of the first body relative to the second.