Dimensional Gauging Using A Scanning Laser

The process for manufacturing a major type of catalytic converter for exhaust pollution control depends upon the availability of a dimensionally precise honeycomb-like ceramic substrate upon which to plate the catalyst metal. Dimensions are important since the cylindrical shaped substrate is later placed within a rigid stainless steel container where close fit is necessary to prevent "blowby". This paper will present a multiple scanning laser technique which was employed to automatically measure diameter in several planes of the still soft ceramic cylinder during the extrusion process.