Measurement of profiles of irregular objects

摘要

The profile of an irregular shaped object is measured in an in-line extrusion process. This entails passing the object through an optical measuring gate which is rotated around the material, as the material intercepts the path of the beam across the gate. The intercepted beam is then monitored by suitable means to determine the shape of the profile. This assists inter alia in maintaining control of the size of the material and conformity to the required specification. The measuring gate includes a light source which directs a beam towards a photocell, the source and photocell being mounted on rings which are reciprocated through angles of 180 DEG around the object as it is extruded. The thickness of a coating on the object may be determined by using respective apparatuses to determine the object's diameter before and after coating. The object may be an electrical cable.