According to DIN 3140 a centering error is present when the optical and the reference axis of a lens do not coincide, i.e. these are different in position or direction. During the process of cementing, alignment and bonding of lenses in a mount, significant centering errors could result and add to the machining errors of a lens. Consequently, the requirements of a high performance optical system can be fulfilled only when all the production steps from the centering tolerance measurement to the assembly of the lens in a mount are planned and designed as an integrated concept. The comprehensive TRIOPTICS line of equipment -under the generic name OptiCentric- has been specifically designed to cover applications related to any type of optical components and to respond to different accuracy degrees. The OptiCentric-System also covers all the production steps from the centration measurement to the alignment, cementing and assembly of optics. The OptiCentric-System includes valuable tools, from simple and affordable visual instruments to complex, fully automated and PC-controlled production and laboratory stations.
 
In a typical set up an autocollimator equipped with an additional head lens is focussed to the image plane of the sample (transmission method) or to the centre of curvature of the lens surface under test (reflection method). The focussing procedure and the operation of the instrument can be performed either manually or controlled by PC.