Method of qualitatively ascertaining the position and degree of severity of chatter marks in a fine-machined surface of a workpiece

The invention relates to a method of contactlessly ascertaining chatter marks in finely-machined workpiece surfaces, with the following steps: a contactlessly operating, high-resolution surface-measuring method is used to generate from the workpiece surface a data record representing the actual microtopography of the workpiece surface, to take away from this a data record representing the idealized macroform of the workpiece surface, and in this way to generate a data record representing the flat-extended form of the microtopography of the workpiece surface. This data record is subjected to a digital in-phase bandpass filtering with respect to its circumferential waviness, the waviness of interest here of the chatter marks preferably being allowed through. The data record formed in this way is for its part subjected to a stationary multiple cross correlation with respect to the transverse direction. This produces an only two-dimensional data record representing the circumferential position of any chatter marks on the workpiece surface and their degree. To form a characteristic assessment number for chatter marks, the chatter-mark data record can be further evaluated, for example by two-stage averaging.