NIST SURFACE ROUGHNESS AND STEP HEIGHT CALIBRATIONS, Measurement Conditions and Sources of Uncertainty

Parameters of surface roughness and step height are currently measured at the National Institute of Standards and Technology (NIST) by means of a computerized/stylus instrument. For roughness height parameters, we use a calibration ball as a master to calibrate the instrument to be employed during a measurement. Profiles of the calibrating master and the roughness sample under test are stored in a computer. For roughness spacing parameters, we use an interferometrically calibrated Standard Reference Material (SRM) to check the calibration of the drive-axis encoder of the stylus instrument.