抄録
The surface roughness of sandpaper specimens with alumina abrasive was measured based on the effective reflectivity of terahertz waves. Measurement results based on the frequency dependence of the effective reflectivity were in agreement with measurement results using a contact surface roughness gauge to within 10% for surface roughness 10-35 µm. In addition, the frequency-averaged effective reflectivity was calculated with the surface roughness as a parameter. This provided a calibration curve to convert the measured frequency-averaged effective reflectivity to surface roughness. Measurement results based on the frequency-averaged effective reflectivity were in agreement with measurement results using a contact surface roughness gauge for surface roughness below 25 µm. The effect of the paint layer coating the abrasive did not result in significant error. The results showed that terahertz waves can be used for noncontact measurement of the surface roughness of dielectric surfaces.
