A storage and retrieval system of pallets for handling of work pieces. The resin molded article for an optical element which comprises first surface portion at a part of the surface of a resin molded base and comprises a hollow portion found by injecting a fluid into the inside of the base from the outside. The coating compositions may further include a mixture of hydrolysis products and partial condensates of one or more silane additives, a colloidal silica material, and a tetrafunctional silane. A strain gauge of this type can be used in a force-measuring cell, where the surface-smoothing layer and the protective coating can be deposited after an uncoated strain gauge has been installed on the deformable body of the force-measuring cell. When the projection is engaged in the associated guide support hole, the guiding part guides the suspension arm at a suitable position. Programming on the controller determines a lateral position of the pattern relative to a reference position associated with the work surface based on the pattern image captured by the camera and a height the pattern above the work surface based on the lateral position of the pattern.