Measurement uncertainty

The uncertainty of the Gannen probe is influenced by its repeatability, thermal drift, tip deviations and workpiece deformation. The combined 3D uncertainty of the sensor is 50 nm.

3D sensor uncertainty *		14 nm
Deviations due to sphere **	<	45 nm
Temperature deviations	<	10 nm
Deviations due to material deformation	<	10 nm
Other deviations	<	10 nm
Combined 3D uncertainty		50 nm

* The analysis is based on a maximum displacement of the sensor tip of 10 micrometers in a temperature controlled environment, where temperature variations are within plusminus 0,1 K.

** Deviations due to roughness and unroundness of the sensor tip can be compensated for during the measurement. The uncertainty in this compensation is the main contribution to the uncertainty of the sensor.