... measurement: Ra, Rz, Rq, Rt 2)Highly sophisticated inductance sensor Surface Roughness Tester:1)Multiple parameter measurement: Ra, Rz, Rq ... causes displacement of the probe which results in change of inductive amount of induction coils so as to generate analogue ... parameter measurement: Ra, Rz, Rq, Rt* Highly sophisticated inductance sensor* Four wave filtering methods : RC, PC-RC, GAUSS and D ...