Setup and procedure of optical reflectometry to check the stage of finishing during the abrasive magneto-rheological polishing of glass surface

A setup and a procedure of monitoring the stage of the magnetorheological abrasive finishing of glass surface by means of optical diffuse reflectometry is shortly described and a concrete application based on a transformed integral photometer in a reflectometer is proposed. Three mirrors of optical quality, two to re-direct the light beam and one as reflective reference surface are used. Specimens of two crown glasses, the indigene equivalent of BK 7 (Germany) and a Russian optical glass with TK 121 code were successively polished with an original installation of magnetorheological finishing (MRF), and their momentary reflective characteristics were photometrically checked in a transformed photometer after pre-established intervals of processing, 10 min and 15 min respectively. A special demountable support for the processed specimen was conceived. It permitted to make the measurement without detaching the processed optical piece blocked on it. The very good sensitiveness and reproducibility of the photometric measurements are graphically presented and interpreted.