An apparatus and a method for measuring very small separations between a transparent or semi-transparent first body and a second body, wherein one or more light sources produce light that is split into two distinct paths. Wherein the thin-film circuit layer has an external circuitry, which is electrically connected to the metal pads of the dies, that extends to a region outside the active surface of the dies for fanning out the metal pads of the dies. The reel is supported on the frame. The movable anchor lug and the movable base may be lifted and extended to form an upper and a lower open space for the pulley such that the cord may be wound rapidly without obstruction. A dielectric layer is then formed over the floating gates followed by the forming of a control gate. The arm of the cylinder is extended to push the joint of the articulated member to an over-center position, thereby locking the articulated member.