Accuracy of a 3D scanning instrument relates to the error by which the scan data points deviate from the actual location of the point with respect to the physical part. The lower the error, the higher the accuracy of the scan data.
On the other hand, the resolution of a 3D scanning instrument relates to the density of the data points the instrument can capture i.e. the number of data points within a unit area of the surface of the part. Just like the number of pixels defines the resolution of a 2D image, it is the number of scan data points that defines the resolution of the scan data. It is also measured as the distance between the closest data points. The lower the distance between the data points, the higher the resolution of the scan data.
Among other factors, the size and shape of the part being scanned heavily influence the accuracy and the resolution levels which one can expect from the scan data. The high resolution which may be required to get an accurate scan data of a complex contoured surface may not be required to get an accurate scan data of a simple geometric part.
In general, as the part size increases, the accuracy and the resolution of the 3d scan decreases.
We also consider the end-use application of the scan-data to use the optimum lens for the 3d scanning project. For eg, 3D scanning for tool inspection demands a much higher accuracy level than 3D scanning a part for proof-of-concept designing.
