Standard Roughness Calibration Block Multi-engraved lines (Square Wave)
Made by optical glass, with high hardness, high accuracy standard roughness value, anti-scratch, has longer life than metal roughness block.
Meet standard GB/T19067.1-2003 and ISO5436-1:2000
Approximation: Ra=0.1um, 0.2um, 0.4um, 0.8um, 1.6um, 3.2um, 6.4um
Customized Value and Sine Wave available.