Optical positioning system for high temp. test specimen - uses lens forming image of specimen on photocell whose output controls servo positioning mechanism

摘要

The procedure for locating the position of a test specimen working at a high temperature includes observation of the light emitted, by an opto-electronic system coupled to a servomechanism, which controls the specimen position in response to the output signal. A lens (44) whose plane is parallel to the axis of the cylindrical specimen (21) projects an image of the specimen on to a photosensitive cell (42) forming part of the servo control system (41). The output of the servo control system operates a motor (38) which controls the positioning of the specimen. The servo control system also includes an analogue gate whose opening and closing is controlled according to the output of an optical pyrometer (75) focussed on to the front surface (22) of the specimen. The specimen may be subjected to a laser beam and erosion by hot gases, and must be kept in position.