An apparatus for determining the surface roughness of a material.

摘要

An apparatus (30) for determining the surface roughness of a material (10) comprises an acoustic element (32) which is pivotally mounted to a fixed support structure (38). The acoustic element (32) has a polished end (34) which is urged into contact with the surface of the material by a spring (40). The material (10) is caused to move relative to the acoustic element (32) by a driven roller (12). A transducer (42) is acoustically coupled to the acoustic element (32) and the transducer (42) detects stress waves propagating in the acoustic element (32) as a result of the generation of stress waves by the frictional and impact forces produced by the rubbing of the acoustic element (32) and the material (10). The stress wave activity is dependent on the surface roughness of the material. A processor (46) analyses an electrical signal produced by the transducer to determine the surface roughness of the material. The processor (46) may analyse the electrical signal produced by the transducer to determine the presence of impurities on the surface of the material.