This section discusses measurement results using the Gannen 3D tactile sensor.

The repeatability of the Gannen probe is measured using the calibration setup. Over a 10 micrometer measurement range, the standard deviation of the measurement signal is typically 2 nm or less for a single measurement direction. The combined 3D standard deviation of the probe is typically 4 nm over this range.
See the results of our repeatability measurements.

Measurement results show a maximum top-top deviation of 2 nm over any 20 minute interval over a 60 hour measurement.
Go to the drift measurement and thermal stability section.

The combined 3D uncertainty of the Gannen-XP is 50 nm. The main limitation is the compensation of unroundness and roughness of the sensor tip.
The uncertainty budget for the Gannen-XP sensor.

For optimum accuracy, each sensor is calibrated to obtain the relationship between the displacement of the sensor tip and the measurement signals produced by the probe. Deviations due to assembly and manufacturing are thus greatly reduced. Calibration of the sensor can be performed on the CMM itself or using the calibration setup discussed in the next section.
Follow this link if you are interested in the calibration procedure.

The calibration setup uses a flat mirror differential laser interferometer to measure a displacement of the measurement mirror relative to the reference mirror. The uncertainty of the setup is 5 nm over a 30 micrometer range.
Would you like to learn more about the operation of the calibration setup?