Apparatus for regulating the operation of a plant for the making of extruded products

摘要

The apparatus has a measuring head (34) for contact-free optical monitoring of a swelling (A) of material immediately behind the extruder nozzle (22) or a pileup (32) of material ahead of the calibrating tool (26) of the plant. The measuring head (34) has spaced-apart confronting light emitting and light receiving surfaces (52) and (54). Each of these surfaces is adjacent the ends of a plurality of light conducting elements which extend to a housing (38) for a light sender and a light detector. The light receiving surface (54) is subdivided into a plurality of fields (1-13). A first signal identifies at least one field (2-13) which is located at the level of one edge of the extruded product in the region of the swelling or pileup. A second signal denotes the position of the edge within such field (2-13). A single compensation field (1) serves to ascertain a reference value of the intensity of light.