Profilometers measure surface profile and form in addition to roughness parameters, providing detailed topographical data for precision surfaces. Calibration verifies stylus condition, vertical and horizontal axis accuracy, and parameter computation using certified reference specimens. Advanced profilometers measure waviness, form, and contour in addition to roughness.
Inspect the stylus tip under magnification for wear, chipping, or contamination. Verify the stylus tip radius is within specification using a certified tip radius specimen. A degraded stylus produces smoothed profiles and reduced roughness readings.
Using a certified step-height specimen, verify the vertical axis accuracy at multiple amplitudes. Test at a minimum of three step heights spanning the instrument's vertical range. Calculate the error at each height.
Using a certified spacing specimen or precision grating, verify the horizontal traversing accuracy. Measure the known pitch at multiple positions across the traverse length. Calculate the spacing error.
Measure certified roughness reference specimens (Ra, Rz) at a minimum of three roughness levels spanning the measurement range. Compare measured parameters to certified values.
Verify that the Gaussian filter implementation produces correct results by measuring a specimen with known roughness at different cutoff lengths. Compare results to the certified values at each cutoff.
Record all calibration data, reference specimen IDs and certified values, stylus condition assessment, and measurement uncertainty. Issue the calibration certificate and apply the calibration label.
Step height error must not exceed ±2% or ±0.02 µm (whichever is larger). Spacing error must not exceed ±1% of the certified pitch. Roughness parameter (Ra) agreement with certified specimens must be within ±10% or ±0.02 µm (whichever is larger).
12 months, with periodic reference specimen checks
A surface roughness tester typically measures only roughness parameters (Ra, Rz) with limited range. A profilometer provides full surface profile measurement including roughness, waviness, and form, often with longer traverse lengths and higher vertical resolution for comprehensive surface characterization.
A certified tip radius specimen with known features (sharp edges or grooves) is measured. The instrument's software analyzes the stylus response to calculate the effective tip radius. A worn stylus shows a larger radius than specification, typically indicating replacement is needed.
The cutoff length determines the wavelength boundary between roughness and waviness components. A longer cutoff includes more waviness in the roughness calculation, generally producing higher Ra values. The correct cutoff depends on the surface being measured and is specified in the measurement standard.
CalibrationOS tracks due dates, stores certificates, and generates audit-ready reports.
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