Photographic scale for high resolution measurement - uses metal foil heat reflector to withstand illumination temp. effects

摘要

A photographically produced scale, partic. for high resolution measuring equipment such as fine balances or analysers, is constructed to withstand high temp. caused by the high scale illumination intensity required, whilst maintaining relatively low production costs. The scale has glass supporting and base plates (11, 14) which are transparent. On the supporting plate is a photographic layer (12) having scale gradiations, which is separated from the base plate by a metal foil mask (13). The mask has an aperture in the region of the scale markings and acts as a thermal reflector. The elements are held together by layers (18) of high temp. two- component adhesive. The mask may be shorter than the other elements to provide a larger adhesive contact area.